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Alpha‐synuclein oligomers play a crucial role in the early diagnosis of Parkinson's disease (PD). In this study, a mercaptoundecanoic acid (MUA)‐capped gold nanorod (GNR)‐coated and chitosan (CH)‐immobilized fiber optic probe has shown considerable sensitivity of its detection. The proposed U‐shaped fiber optic biosensor based on localized surface plasmon resonance (LSPR) was applied to detect α‐syn oligomer (OA) biomarker. By analyzing OA concentrations, the biosensor achieved a limit of detection of (LOD) 11 pM within the concentration range of 10–100 pM and the sensitivity value was found as 502.69 Δλ/RIU. Upon analysis of the CV% (coefficient of variation) and accuracy/recovery values, it is revealed that the sensor successfully fulfilled the criteria for success, displaying accuracy/recovery values within the range of 80%–120% and CV% values below 20%. This sensor presents significant advantages, including high sensitivity, specificity, and ability to detect very low concentrations of OA. In conclusion, the suggested U‐shaped fiber optic biosensor has the potential to be valuable in the early detection of PD from a clinical perspective. [ABSTRACT FROM AUTHOR]

Nanomedicines hold promise for the treatment of various diseases. However, treating cancer metastasis remains highly challenging. In this study, we synthesized gold nanorods (AuNRs) containing (α-GC), an immune stimulator, for the treatment of primary cancer, metastasis, and recurrence of the cancer. Therefore, the AuNR were coated with lipid bilayers loaded with α-GC (α-LA). Upon irradiation with 808 nm light, α-LA showed a temperature increase. Intra-tumoral injection of α-LA in mice and local irradiation of the 4T1 breast cancer tumor effectively eliminated tumor growth. We found that the presence of α-GC in α-LA activated dendritic cells and T cells in the spleen, which completely blocked the development of lung metastasis. In mice injected with α-LA for primary breast cancer treatment, we observed antigen-specific T cell responses and increased cytotoxicity against 4T1 cells. We conclude that α-LA is promising for the treatment of both primary breast cancer and its metastasis. Schematic illustration of α-LA-mediated photo-immunotherapy for treatment of primary tumor and prevention of metastatic lung cancer. [Display omitted] • For PTT, AuNRs were coated with lipid film comprising α-galactosylceramide (α-LA). • α-LA with 808 nm laser irradiation eliminated orthotopic 4 T1 breast cancer by PTT. • α-LA also prevented recurrence of lung metastatic 4 T1 cancer. • Anti-metastatic effect of a-LA was mediated by cancer antigen-specific immunity. [ABSTRACT FROM AUTHOR]

Fabricating robust shape‐memory hydrogels that respond to multiple external stimuli is an important challenge in facilitating gel technology for versatile applications. In this study, we report a simple approach for constructing thermo‐, redox‐, and photo‐responsive hydrogels with high mechanical strength and shape fix/memory capability. Upper critical solution temperature (UCST)‐type amino acid‐based hydrogels were facilely prepared by radical copolymerization of N‐acryloyl glycinamide (NAGAm) with cystine‐derived divinyl acrylamides (ionic cystine [NAC] or nonionic cystine‐methyl ester [NACMe]) units at different monomer concentrations (1/2 M). These hydrogels were transparent and exhibited good mechanical strength (tensile strength of 0.3–0.4 MPa and breaking elongation of 400%–700%). All hydrogels showed UCST‐type swelling‐shrinking behaviors based on thermo‐driven reversible hydrogen bonds among the PNAGAm units, and thus could be fixed into variety of shapes and recovered to the original shape by temperature manipulation. The cystine‐based crosslinkers having SS bonds served as efficient redox‐sensitive and gold‐nanorod‐(AuNR)‐adsorbing moieties; thus, AuNR could be conjugated stably and evenly into the PNAGAm/NAC hydrogel. Moreover, upon light‐irradiation, the AuNR‐conjugated hybrid hydrogel exhibited shape‐memory behavior owing to the photothermal effect of the AuNRs. These multiresponsive/functional hydrogels composed of amino acid units have considerable potential for various applications in the fields of soft actuators and biomedicines. [ABSTRACT FROM AUTHOR]

Chiral assemblies of plasmonic nanocrystals (NCs) are of immense interest due to their distinctive physicochemical characteristics and promising potential in future optoelectronic applications. Despite recent advances in the construction of chiral NC assemblies, most approaches have led to the formation of static irreversible structures with modest optical responses and limited configurational tunability. Herein, a way to prepare a thermally reconfigurable helical assembly of Au nanorods (AuNRs) with a strong chiroptical response is introduced by employing cholesteric liquid crystals (CLCs) as a chiral template. Circular dichroism (CD) spectroscopy and polarized optical microscopy are used to verify the strong chiroptical activity and dynamic optical tunability of chiral plasmonic film of AuNR–CLC composites and to unveil the interactions between constituents. For the system, chiral dopants are employed to induce strong helical procession along the hierarchical structure of the CLC template, resulting in a strong CD response, which can further be enhanced by increasing the amount of AuNRs. Furthermore, the thermotropic nature of the CLC template leads to the reversible on/off switching of the chiroptical responses of the system at a moderate temperature window with almost complete recovery of the original response, suggesting its feasibility as a promising material for chiral optoelectronic devices. [ABSTRACT FROM AUTHOR]

Lead, a prevalent heavy metal, poses significant risks to human health through various exposure pathways. Herein, we propose an extremely sensitive assay toward lead ion (Pb2+) using gold nanorods (GNRs) as probes based on its catalytic activity on etching gold in the presence of 2‐mercaptoethanol and sodium thiosulfate. In the presence of Pb2+, etching predominantly occurs at the two ends of GNRs, leading to the reduction of aspect ratio and the corresponding blueshift of the localized surface plasmon resonance (LSPR). With increasing Pb2+ concentration over the range of 0–50 μM, the color of GNR solution lightens, ultimately becoming colorless. The wavelength shift (Δλ) of LSPR is highly dependent on Pb2+ concentration, with a linear regression equation of Δλ = 10.05ln[Pb2+] + 9.59 and an R2 = 0.995. The assay demonstrates high selectivity for Pb2+ over other potentially interfering ions such as Cu2+ because of its special catalytic activity in the etching of GNRs and the complexing ability of 2‐mercaptoethanol and sodium thiosulfate. Validation of the assay was accomplished by analyzing several forest‐derived food samples, affirming the accuracy in real‐world scenarios. The assay we developed holds promise for many applications in environmental protection and food safety. [ABSTRACT FROM AUTHOR]

Hyperthermia can be integrated with tumor-killing chemotherapy, radiotherapy and immunotherapy to give rise to an anti-tumor response. To this end, a nano-delivery system is built, which can connect hyperthermia and immunotherapy. On this basis, the impact of such a combination on the immune function of dendritic cells (DCs) is explored. The core of this system is the photothermal material gold nanorod (GNR), and its surface is covered with a silica shell. Additionally, it also forms a hollow mesoporous structure using the thermal etching approach, followed by modification of targeted molecule folic acid (FA) on its surface, and eventually forms a hollow mesoporous silica gold nanorod (GNR@void@mSiO 2) modified by FA. GNR@void@mSiO 2 -PEG-FA (GVS-FA) performs well in photothermal properties, drug carriage and release and tumor targeting performance. Furthermore, the thermotherapy of tumor cells through in vitro NIR irradiation can directly kill tumor cells by inhibiting proliferation and inducing apoptosis. GVS-FA loaded with imiquimod (R837) can be used as a adjuvant to enhance the immune function of DCs through hyperthermia. [ABSTRACT FROM AUTHOR]

Malarmugila Manimaran,1,* Yin Yin Teo,2 James Chen Yong Kah,3 Adilet Beishenaliev,1 Yean Leng Loke,2 Yiing Yee Foo,1 Shiow-Fern Ng,4 Chin Fei Chee,5 Sek Peng Chin,6 Farid Nazer Faruqu,1 Chia-Yu Chang,7 Misni Misran,2 Lip Yong Chung,6 Bey Fen Leo,8,* Shih-Hwa Chiou,9,10 Chia-Ching Chang,7,11– 13 Sun Tee Tay,14 Lik Voon Kiew1,7 1Department of Pharmacology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia; 2Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur, Malaysia; 3Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, Singapore, Singapore; 4Centre for Drug Delivery Technology and Vaccine, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia; 5Nanotechnology Catalysis Research Centre, Universiti Malaya, Kuala Lumpur, Malaysia; 6Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universiti Malaya, Kuala Lumpur, Malaysia; 7Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Republic of China; 8Department of Molecular Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia; 9Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China; 10Institute of Pharmacology, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China; 11Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Republic of China; 12Center for Intelligent Drug Systems and Smart Bio-devices, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Republic of China; 13Institute of Physics, Academia Sinica, Nankang, Taipei, Taiwan, Republic of China; 14Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia*These authors contributed equally to this workCorrespondence: Chia-Ching Chang; Lik Voon Kiew, Email ccchang01@nycu.edu.tw; lvkiew@um.edu.myIntroduction: Over 75% of clinical microbiological infections are caused by bacterial biofilms that grow on wounds or implantable medical devices. This work describes the development of a new poly(diallyldimethylammonium chloride) (PDADMAC)/alginate-coated gold nanorod (GNR/Alg/PDADMAC) that effectively disintegrates the biofilms of Staphylococcus aureus (S. aureus), a prominent pathogen responsible for hospital-acquired infections.Methods: GNR was synthesised via seed-mediated growth method, and the resulting nanoparticles were coated first with Alg and then PDADMAC. FTIR, zeta potential, transmission electron microscopy, and UV–Vis spectrophotometry analysis were performed to characterise the nanoparticles. The efficacy and speed of the non-coated GNR and GNR/Alg/PDADMAC in disintegrating S. aureus-preformed biofilms, as well as their in vitro biocompatibility (L929 murine fibroblast) were then studied.Results: The synthesised GNR/Alg/PDADMAC (mean length: 55.71 ± 1.15 nm, mean width: 23.70 ± 1.13 nm, aspect ratio: 2.35) was biocompatible and potent in eradicating preformed biofilms of methicillin-resistant (MRSA) and methicillin-susceptible S. aureus (MSSA) when compared to triclosan, an antiseptic used for disinfecting S. aureus colonisation on abiotic surfaces in the hospital. The minimum biofilm eradication concentrations of GNR/Alg/PDADMAC (MBEC50 for MRSA biofilm = 0.029 nM; MBEC50 for MSSA biofilm = 0.032 nM) were significantly lower than those of triclosan (MBEC50 for MRSA biofilm = 10,784 nM; MBEC50 for MRSA biofilm 5967 nM). Moreover, GNR/Alg/PDADMAC was effective in eradicating 50% of MRSA and MSSA biofilms within 17 min when used at a low concentration (0.15 nM), similar to triclosan at a much higher concentration (50 μM). Disintegration of MRSA and MSSA biofilms was confirmed by field emission scanning electron microscopy and confocal laser scanning microscopy.Conclusion: These findings support the potential application of GNR/Alg/PDADMAC as an alternative agent to conventional antiseptics and antibiotics for the eradication of medically important MRSA and MSSA biofilms.Keywords: biofilm, gold nanorod, S. aureus, PDADMAC, MRSA, MSSA

4D printing is the 3D printing of objects that change chemically or physically in response to an external stimulus over time. Photothermally responsive shape memory materials are attractive for their ability to undergo remote activation. While photothermal methods using gold nanorods (AuNRs) are used for shape recovery, 3D patterning of these materials into objects with complex geometries using degradable materials is not addressed. Here, the fabrication of 3D printed shape memory bioplastics with photo‐activated shape recovery is reported. Protein‐based nanocomposites based on bovine serum albumin (BSA), poly (ethylene glycol) diacrylate (PEGDA), and AuNRs are developed for vat photopolymerization. These 3D printed bioplastics are mechanically deformed under high loads, and the proteins served as mechano‐active elements that unfolded in an energy‐dissipating mechanism that prevented fracture of the thermoset. The bioplastic object maintained its metastable shape‐programmed state under ambient conditions. Subsequently, up to 99% shape recovery is achieved within 1 min of irradiation with near‐infrared (NIR) light. Mechanical characterization and small angle X‐ray scattering (SAXS) analysis suggest that the proteins mechanically unfold during the shape programming step and may refold during shape recovery. These composites are promising materials for the fabrication of biodegradable shape‐morphing devices for robotics and medicine. [ABSTRACT FROM AUTHOR]

During morphological evolution of gold nanoparticles, amino acids play a vital role in tuning shape, introducing chirality and inducing facet selective reactivity. Herein, we report the synthesis of unique marigold like structure (MGS) via growth reaction of methionine (Met) incubated positively charged anisotropic gold nanorod (GNR). Varying three important parameters such as growth time, concentration of Met and Au3+ reveals the combination of freshly generated small nucleated particles (fNPs) and GNR towards fabricating the unique MGS containing disk and ray floret parts. Strong interaction between Met and (111) plane of Au0 controls the orientation of (111) plane parallel to the direction of growth. This preferential interaction directs the assembly of gold nanostructures through Au (200) plane and results in merging of fNPs with concave GNR (cGNR) to fabricate the external arrangement of ray floret structure. The structural selectivity is attributed to the electron donating capacity of thioether functional group of Met(S) to Au+, generated prior to secondary nucleation. As confirmed by XPS and ζ‐potential analysis, the above interaction controls the Met concentration dependent inhibition of further Au+→Au0 reduction. The growth strategy of GNR has been further validated with a Met enriched peptide to produce disk and ray florets. [ABSTRACT FROM AUTHOR]

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Wang L, Li D, Hao Y, et al. Int J Nanomedicine. 2017;12:3059-3075. The authors have advised Figures 9 and 11 on pages 3070 and 3071, respectively, are incorrect. The H&E staining image of tumor tissue in the PLGA/DTX@MnO2 group in Figure 9C and the X-ray CT images in Figure 11C were inadvertently misused during data acquisition. The correct Figure 9 is as follows. Figure 9 Inhibition of tumor growth in vivo by the drug delivery system.Abbreviations: H&E, hematoxylin and eosin; AuNR, gold nanorod; DTX, docetaxel; MnO2, manganese dioxide; PLGA, poly(lactic-co-glycolic acid); RF, radiofrequency.Notes: (A) Relative volumes of tumor-bearing mice; (B) body weight of the mice models (mean ± standard deviation; n=6); (C) H&E-stained tumor tissue sections: (a) control, (b) DTX, (c) PLGA/DTX@MnO2, (d) PLGA/DTX@MnO2 + RF, (e) PLGA/AuNR/DTX@MnO2, and (f) PLGA/AuNR/DTX@MnO2 + RF. The correct Figure 11 is as follows. Figure 11 Dual-mode imaging in vivo.Abbreviations: MR, magnetic resonance; CT, computed tomography.Notes: (A, B) T1-weighted MR images; (C) X-ray CT images: (a) control; (b) 4 h; (c) 8 h. The authors apologize for these errors and advise they do not affect the results and conclusions of the paper.

Methicillin‐resistant Staphylococcus aureus (MRSA) is one of the deadliest pathogenic bacteria. Using photothermal therapy (PTT) to eradicate MRSA bacteria easily and effectively, it has directed this bacterium to be destroyed. Gold nanorods (AuNRs), which are nanoparticles that provide PPT, were synthesized and removed from the CTAB molecule reduce the toxic effect caused by CTAB. Subsequently, mercaptophenylboronic acid (MFBA) coated AuNRs were synthesized and used in photothermal therapy to develop a targeting agent to selectively eliminate MRSA. A decrease in cytotoxic effect of CTAB@AuNRs after conjugation with MFBA was also demonstrated by the MTS cell viability test. We found that at the end of 48 hours and 72 hours of interaction, IC50 values of MFBA@ AuNR increased by approximately 50 % compared to CTAB@AuNR. Also, it shows that the cytotoxicity of AuNRs conjugated with MFBA was reduced. Herein, photothermal efficiency was achieved with MFBA@AuNRs targeting MRSA. The purpose of using and modifying gold nanorods is to reduce the toxicity of AuNRs and to examine their efficacy on resistant pathogenic bacteria strains by taking advantage of photothermal therapy properties. [ABSTRACT FROM AUTHOR]

In recent years, gold nanomaterials have become a hot topic in photothermal tumor therapy due to their unique surface plasmon resonance characteristics. The effectiveness of photothermal therapy is highly dependent on the shape and size of gold nanoparticles. In this work, we investigate the photothermal therapeutic effects of four different sizes of gold nanorods (GNRs). The results show that the uptake of short GNRs with aspect ratios 3.3–3.5 by cells is higher than that of GNRs with aspect ratios 4–5.5. Using a laser with single pulse energy as low as 28 pJ laser for 20 s can induce the death of liver cancer cells co-cultured with short GNRs. Long GNRs required twice the energy to achieve the same therapeutic effect. The dual-temperature model is used to simulate the photothermal response of intracellular clusters irradiated by a laser. It is found that small GNRs are easier to compact because of their morphological characteristics, and the electromagnetic coupling between GNRs is better, which increases the internal field enhancement, resulting in higher local temperature. Compared with a single GNR, GNR clusters are less dependent on polarization and wavelength, which is more conducive to the flexible selection of excitation laser sources. [ABSTRACT FROM AUTHOR]

A variety of in vitro assays have been designed based on optical imaging to study essential processes for nervous system development, such as neurogenesis and synaptogenesis. However, it is still difficult to assess the developmental processes under culture conditions where uncontrolled neurite growths and numerous neuronal connections occur all at the same time. Moreover, present techniques for in vitro assays lack the ability to induce and evaluate these processes at a specific time point. In this study, we applied a nanoparticle-assisted thermoplasmonic ablation of a cell-repulsive hydrogel to realize assays for two developmental processes: neurite outgrowth and synapse formation. We successfully demonstrated that this technique could guide neurites or make connections at different cultivation times, and the length of growing neurites and the number of forming synapses could be quantified. Our developed method for in vitro assays is expected to be helpful in studying various neurodevelopment processes occurring at different developmental stages. [ABSTRACT FROM AUTHOR]

Biofluid biomarkers, as objective predictors of traumatic brain injury (TBI) pathobiological processes, play an important role in the early detection of TBI. However, the lack of sensitive and rapid detection assays to detect biomarker levels has been an urgent problem. In this study, we devised a novel surface-enhanced Raman scattering (SERS)-based paper lateral flow strip (PLFS) based on gold nanorods (AuNRs) with controlled aspect ratios for the screening and diagnosis of TBI. To improve the sensitivity of the designed device, AuNRs, as the key component of SERS probes, were optimized by controlling the particle morphology, showing great local plasma enhancement. Furthermore, using thionin acetate (THI) as a Raman reporter, the detection performance of PLFS was further improved due to the unique molecular structure of THI. Thus, the constructed PLFS has been demonstrated to be ultrasensitive, with a limit of detection (LOD) reaching ∼10–1 pg·mL–1. Fo r real-world measurements of glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) in blood samples, the results monitored by the SERS assay were exactly consistent with those obtained through the traditional enzyme-linked immunosorbent assay (ELISA). The above result demonstrated that the developed SERS-PFLS has extensive application prospects in the screening and diagnosis of TBI in the emergency department as point-of-care testing (POCT) and may further shift the paradigm of TBI patient management and clinical outcome in emergency departments. [ABSTRACT FROM AUTHOR]

To optimize synergistic breast cancer treatment, a nanocomposite was fabricated with pH-temperature responsive and chemo-photothermal combination therapy. Herein, gold nanorods (AuNRs) are coated with [poly[(N-isopropylacrylamide)-co-(methacrylic acid)] (p(NIPAM-co-MAA)) modified mesoporous silica (MS) for Doxorubicin (DOX) delivery (AuNR@DOX-MS@p(NIPAM-co-MAA)). Upon NIR radiation, the AuNR core induced hyperthermia via generating heat. Simultaneously, the polymer layer collapsed in response to high temperature/low pH, which allowed the triggering of DOX release from the MS shell at the tumor site. With this nanocomposite, nearly zero premature release of DOX at physiological pH/temperature was detected, while effective DOX release was reported at higher temperature/lower pH values. In addition, in vitro studies demonstrated that the nanocomposite has a substantial uptake efficiency of MDA-MB-231 breast cancer cells, with a significant increase in suppressing MDA-MB-231 ​cell proliferation in response to laser irradiation. The in vivo experiments further verified the high efficiency of the fabricated nanocomposite in accumulating at the tumor site and the good capability in suppressing tumor growth in the mice upon intravenous injection, while exhibiting good biosafety in relation to major organs in the body. Thus, the synthesized nanocomposite could be a potential nanocarrier for breast cancer treatment with synergistic chemo-photothermal therapeutic capability.

In recent years, gold nanomaterials have become a hot topic in photothermal tumor therapy due to their unique surface plasmon resonance characteristics. The effectiveness of photothermal therapy is highly dependent on the shape and size of gold nanoparticles. In this work, we investigate the photothermal therapeutic effects of four different sizes of gold nanorods (GNRs). The results show that the uptake of short GNRs with aspect ratios 3.3–3.5 by cells is higher than that of GNRs with aspect ratios 4–5.5. Using a laser with single pulse energy as low as 28 pJ laser for 20 s can induce the death of liver cancer cells co-cultured with short GNRs. Long GNRs required twice the energy to achieve the same therapeutic effect. The dual-temperature model is used to simulate the photothermal response of intracellular clusters irradiated by a laser. It is found that small GNRs are easier to compact because of their morphological characteristics, and the electromagnetic coupling between GNRs is better, which increases the internal field enhancement, resulting in higher local temperature. Compared with a single GNR, GNR clusters are less dependent on polarization and wavelength, which is more conducive to the flexible selection of excitation laser sources.

Interest in moving from 3D printing to 4D printing, which would enable rapid and precise motion in reaction to a given stimulus, is evolving. Thermally responsive hydrogels are one of the most common types of soft 4D devices. They are capable of changing shape or behavior autonomously in a manner resembling natural movement, and a bio‐inspired soft actuator has been fabricated by combining stimuli‐responsive nanoparticles with 3D printable hydrogels. We formulated and tested an N‐isopropylacrylamide (NIPAm) and polyethylene glycol thiol‐coated gold nanorod (P‐AuNR) hydrogel nanocomposite as an active ink material for use in the fabrication of heat‐sensitive soft actuators for photo‐responsive soft robotic motions. Due to their surface plasmon resonance (SPR), those highly dispersible P‐AuNR was able to absorb near‐infrared (NIR) light and release heat into their surroundings. This system was not immersed in water and reacted quickly and sensitively to NIR exposure. The 3D structure designed and fabricated with these inks was able to deform selectively only in a very localized part in response to non‐contact external stimuli, leading to various types of controlled shape‐morphing. [ABSTRACT FROM AUTHOR]

Conformation of biomolecules like DNA, peptides and amino acids play vital role during nanoparticle growth. Herein, we have experimentally explored the effect of different noncovalent interaction between a 5′‐amine modified DNA sequence (NH2−C6H12‐5′‐ACATCAGT‐3′, PMR) and arginine during the seed‐mediated growth reaction of gold nanorods (GNRs). Amino acid‐mediated growth reaction of GNRs results in a snowflake‐like gold nanoarchitecture. However, in case of Arg, prior incubation of GNRs with PMR selectively produces sea urchin‐like gold suprastructures, via strong hydrogen bonding and cation‐π interaction between PMR and Arg. This distinctive structure formation strategy has been extended to study the structural modulation caused by two structurally close α‐helical RRR (Ac‐(AAAAR)3A−NH2) peptide and the lysine mutated KKR (Ac−AAAAKAAAAKAAAARA−NH2) peptide with partial helix at the amino terminus. Simulation studies confirm that a greater number of hydrogen bonding and cation‐π interaction between the Arg residues and PMR resulted in the gold sea urchin structure for RRR peptide against KKR peptide. [ABSTRACT FROM AUTHOR]

CRISPR-Cas systems (clustered regularly interspaced short palindromic repeats) have shown great potential as efficient gene editing tools in disease therapeutics. Although numerous CRISPR-Cas systems have been developed, detailed mechanisms of target recognition and DNA cleavage are still unclear. In this work, we dynamically observe the entire process of conjugation, target recognition and DNA cleavage by single particle spectroscopy of CRISPR-Cas systems on single particle surfaces (gold) with the unique advantage of extended time periods. We show the CRISPR-Cas system, comprised of Cas endonuclease and single guide RNA, is stable and functional on single particle surfaces. Owing to the photostability of single particle surfaces, we directly observe in real time the entire dynamic process of conjugation, target recognition and DNA cleavage without photobleaching. We find heterogeneity in target recognition and DNA cleavage processes in which individual spectra vary significantly from one another as well as from the ensemble. We believe an in depth understanding of heterogeneities in CRISPR-Cas systems can overcome potential barriers in precision medicine and personalized disease therapeutics.

Abstract Background Cancer nanomedicines based on synthetic polypeptides have attracted much attention due to their superior biocompatibility and biodegradability, stimuli responsive capability through secondary conformation change, adjustable functionalities for various cargos such as peptides, proteins, nucleic acids and small therapeutic molecules. Recently, a few nanoformulations based on polypeptides comprising NK105, NC6004, NK911, CT2103, have entered phase I-III clinical trials for advanced solid tumors therapy. In the current study, we prepared polypeptide-based vesicles called peptosome via self-assembly of amphiphilic polypeptide-based PEG-PBLG diblock copolymer. Results In this regard, poly(γ-benzyl L-glutamate (PBLG) was synthesized via ring opening polymerization (ROP) of γ-benzyl L-glutamate-N-carboxyanhydride (BLG-NCA) using N-hexylamine as initiator. Then amine-terminated PBLG was covalently conjugated to heterofuctional maleimide PEG-carboxylic acid or methyl-PEG-carboxylic acid. The PEG-PBLG peptosomes were prepared through double emulsion method for the co-delivery of doxorubicin.HCl and gold nanorods as hydrophilic and hydrophobic agents in interior compartment and membrane of peptosomes, respectively (Pep@MUA.GNR-DOX) that DOX encapsulation efficiency and loading capacity were determined 42 ± 3.6 and 1.68 ± 3.6. Then, theranostic peptosomes were decorated with thiol-functionalized EpCAM aptamer throught thiol-maleimide reaction producing Apt-Pep@MUA.GNR-DOX for targeted delivery. The non-targeted and targeted peptosomes showed 165.5 ± 1.1 and 185 ± 4.7 nm diameters, respectively while providing sustained, controlled release of DOX. Furthermore, non-targeted and targeted peptosomes showed considerable serum stability. In vitro study on MCF-7 and 4T1 cells showed significantly higher cytotoxicity for Apt-Pep@MUA.GNR-DOX in comparison with Pep@MUA.GNR-DOX while both system did not show any difference in cytotoxicity against CHO cell line. Furthermore, Apt-Pep@MUA.GNR-DOX illustrated higher cellular uptake toward EpCAM-overexpressing 4T1 cells compared to Pep@MUA.GNR-DOX. In preclinical stage, therapeutic and diagnostic capability of the prepared Pep@MUA.GNR-DOX and Apt-Pep@MUA.GNR-DOX were investigated implementing subcutaneous 4T1 tumor model in BALB/c mice. The obtained data indicated highest therapeutic index for Apt-Pep@MUA.GNR-DOX compared to Pep@MUA.GNR-DOX and free DOX. Moreover, the prepared system showed capability of CT imaging of tumor tissue in 4T1 tumorized mice through tumor accumulation even 24 h post-administration. Conclusion In this regard, the synthesized theranostic peptosomes offer innovative hybrid multipurpose platform for fighting against breast cancer. Graphical Abstract

Gold nanorods (GNRs/AuNRs) are a group of gold nanoparticles which their simple surface chemistry allows for various surface modifications, providing the possibility of using them in the fabrication of biocompatible and functional nano-agents for cancer therapy. AuNRs, moreover, exhibit a maximum absorption of longitudinal localized surface plasmon resonance (LSPR) in the near-infrared (NIR) region which overlaps with NIR bio-tissue 'window' suggesting that they are proper tools for thermal ablation of cancer cells. AuNRs can be used for induction of mono or combination therapies by administering various therapeutic approaches such as photothermal therapy (PTT), photodynamic therapy (PDT), chemotherapy (CT), radiotherapy (RT), and gene therapy (GT). In this review, anticancer therapeutic capacities of AuNRs along with different surface modifications are summarized comprehensively. The roles of AuNRs in fabrication of various nano-constructs are also discussed. [Display omitted] • Gold nanorods are versatile platforms for cancer therapy. • Gold nanorods are able to induce photothermal therapy upon NIR irradiation. • Gold nanorods are proper platforms for combining different therapeutic modalities. [ABSTRACT FROM AUTHOR]

A cytopathology test for cervical cancer diagnosis has been introduced to complement the histopathology test. This study developed a new cervical cancer diagnostic method that complements the existing liquid cytology to reduce the diagnostician's skill dependence and to improve diagnostic accuracy. With the ease of introduction of surface functional groups and their high biocompatibility and stability, gold nanomaterials have been used to diagnose numerous biomolecules. CA125 and p16 markers were chosen as protein markers uniquely present in cervical cancer. Bioconjugation technology was used to form a stable bond between the target antibody and gold nanorods. Antibody-gold nanorods were administered to cervical cancer cells as a factor for optical microscopic analysis. The degree of cancer cell labeling was determined through additional fluorescence microscopy analysis. Additionally, a liquid-based cytology test mimicking the clinical environment was prepared, and the false-positive rate, false-negative rate, and accuracy were determined when the study strategy was implemented. The strategy validated in this study (antibody-gold nanorod-based cervical cancer diagnosis) suggests a method that can reduce the dependence on experts for the cancer cytology and can increase test accuracy. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides have been demonstrated to display an immediate response to a large set of pathogenic activity against viruses, bacteria, and fungi by virtue of their local binding with phospholipid phosphatidylserines to exert cytotoxic effect. Plasmonic nanostructures are particularly appealing in medical diagnostics and therapeutics owing to their biocompatibility and ease of surface modification. The current article reports a development of ε‐poly‐l‐lysine modified gold nanorod (PLL‐AuNR) Raman‐active system that can be used to target pathogenic bacteria along with rapid monitoring of antimicrobial action from environmental samples. Result indicates a remarkable change in Raman enhancement factor from 1.49 × 104 to 2.17 × 107 after addition of Salmonella, Bacillus subtilis, and Escherichia coli bacteria in PLL‐AuNR colloid, enabling a large optical window to monitor the process of pathogenic action. Antimicrobial assay with PLL‐AuNR reveals significantly high cytotoxic values of ~92% in E. coli, ~90% in B. subtilis, and ~87% in Salmonella compared with their respective responses in bare PLL, which shows ~37% in E. coli, ~32% in B. subtilis, and ~27% in Salmonella, which proportionally collaborates with change in surface‐enhanced Raman spectroscopy (SERS) intensity beyond 10 min of incubation time. Major experimental design parameters and possible mechanism that relates unusual plasmonic enhancement and antimicrobial action of PLL‐AuNR system have also been discussed. [ABSTRACT FROM AUTHOR]

To optimize synergistic breast cancer treatment, a nanocomposite was fabricated with pH-temperature responsive and chemo-photothermal combination therapy. Herein, gold nanorods (AuNRs) are coated with [poly[(Nisopropylacrylamide)- co-(methacrylic acid)] (p(NIPAM-co-MAA)) modified mesoporous silica (MS) for Doxorubicin (DOX) delivery (AuNR@DOX-MS@p(NIPAM-co-MAA)). Upon NIR radiation, the AuNR core induced hyperthermia via generating heat. Simultaneously, the polymer layer collapsed in response to high temperature/low pH, which allowed the triggering of DOX release from the MS shell at the tumor site. With this nanocomposite, nearly zero premature release of DOX at physiological pH/temperature was detected, while effective DOX release was reported at higher temperature/lower pH values. In addition, in vitro studies demonstrated that the nanocomposite has a substantial uptake efficiency of MDA-MB-231 breast cancer cells, with a significant increase in suppressing MDA-MB-231 cell proliferation in response to laser irradiation. The in vivo experiments further verified the high efficiency of the fabricated nanocomposite in accumulating at the tumor site and the good capability in suppressing tumor growth in the mice upon intravenous injection, while exhibiting good biosafety in relation to major organs in the body. Thus, the synthesized nanocomposite could be a potential nanocarrier for breast cancer treatment with synergistic chemo-photothermal therapeutic capability. [ABSTRACT FROM AUTHOR]

To develop an effective treatment strategy to simultaneously avoid fatal adverse effects in the treatment of oral cancer, combination therapy has been explored because of its multiple functions. This work aims to develop a novel type of gold-nanorod-based nanomaterials decorated with tetrahedral DNA nanostructures (TDN) carrying antitumor drugs, namely, GNR@TDN-DOX nanocomposites. In the designed structure, TDN, with a three-dimensional geometry composed of DNA strands, can provide GC base pairs for binding with the anticancer drug doxorubicin (DOX). The photothermal heating properties, biocompatibility properties, and antitumor performance of obtained GNR@TDN-DOX nanocomposites were investigated to assess their application potential in tumor treatment. Systematic studies have shown that the obtained GNR@TDN-DOX nanocomposites have high photothermal conversion under the illumination of an 808-nm infrared laser, leading to effective antitumor applications. In addition, the cell viability study shows that GNR@TDN-DOX nanocomposites have good biocompatibility. In vitro studies based on A375 cells show that the GNR@TDN-DOX nanocomposites can effectively eliminate cancer cells because of the combination of photothermal therapy induced by GNRS and chemotherapy induced by TDN-carrying DOX. The result shows that the obtained GNR@TDN-DOX nanocomposites have efficient cellular uptake and lysosome escape ability, together with their nuclear uptake behavior, which results in a significant antitumor effect. This work has demonstrated a potential nanoplatform for anticancer applications. [ABSTRACT FROM AUTHOR]

Neuromodulation has made great strides in recent years, but in vitro studies have been limited to two-dimensional cell cultures, far from in vivo conditions. In this study, we realized a novel thermoplasmonic platform for modulating the neural activity of three-dimensional cell cultures, providing a new tool to bring in vitro neuromodulation studies into a three-dimensional environment. The photosensitive scaffold, obtained by covering soda-lime glass microbeads (diameter about 40 µm) with gold nanorods, integrates microbeads' structural properties, intended to support the development of the neural network in three dimensions, with the photothermal properties of plasmonic nanoparticles. We demonstrate its efficiency in providing support for the construction of three-dimensional cell culture and how, under Near-infrared laser irradiation, their photothermal effect can precisely and non-invasively modulate the activity of the neural network. Our platform is expected to be a useful tool for improving neural network studies to better understand complex brain functions and neural disorders. [ABSTRACT FROM AUTHOR]

The crowded intracellular environment of biomolecules, including organelles, solutes, proteins, and membranes, presents distinct biomolecular dynamics crucial for the functions of biomolecules within living cells. However, background suppression is critical to uncover nanoscale dynamics in living cells. Herein, a new method for enabling rapid, nanoscale background elimination of cellular metallic nanoprobes is presented. By employing integrated nanoscopic correction (iNC) designed to eliminate depolarization effects, which compromise background elimination, a real‐time algorithm to subtract and increment orthogonal pairs of polarizations for real‐time nanoscale background elimination is introduced. The ability to analyze orthogonal pairs at high speed over the entire polarization range is currently difficult to achieve using conventional methods. By processing orthogonal pairs in real time, this method minimizes movement artifacts during the background elimination process. Nanometer spatial stability which enables two orders of magnitude increase in signal‐to‐noise ratio of cellular metallic nanoprobes is shown. Nanoscale background elimination aiding the ability to accurately track biomolecules and their dynamics in living cells is anticipated. [ABSTRACT FROM AUTHOR]

Since the angiotensin-converting enzyme 2 (ACE2) protein is abundant on the surface of respiratory cells in the lungs, it has been confirmed to be the entry-point receptor for the spike glycoprotein of SARS-CoV-2. As such, gold nanorods (AuNRs) functionalized with ACE2 ectodomain (ACE2ED) act not only as decoys for these viruses to keep them from binding with the ACE2-expressing cells but also as agents to ablate infectious virions through heat generated from AuNRs under near-infrared (NIR) laser irradiation. Using plasmid containing the SARS-CoV-2 spike protein gene (with a D614G mutation), spike protein pseudotyped viral particles with a lentiviral core and green fluorescent protein reporter were constructed and used for transfecting ACE2-expressing HEK293T cells. Since these viral particles behave like their coronavirus counterparts, they are the ideal surrogates of native virions for studying viral entry into host cells. Our results showed that, once the surrogate pseudoviruses with spike protein encounter ACE2ED-tethered AuNRs, these virions are entrapped, resulting in decreased viral infection to ACE2-expressing HEK293T cells. Moreover, the effect of photothermolysis created by ACE2ED-tagged AuNRs under 808-nm NIR laser irradiation for 5 min led to viral breakdown. In summary, ACE2ED-tethered AuNRs with dual functions (virus decoy and destruction) could have an intriguing advantage in the treatment of diseases involving rapidly mutating viral species such as SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Owing to high surface sensitivity, gold nanorods (AuNRs) are widely used to construct surface-based nanoplasmonic biosensing platforms for label-free molecular diagnostic applications. A key fabrication step involves controlling AuNR deposition onto the target surface, which requires maximizing surface density while minimizing inter-particle aggregation, and is often achieved by surface functionalization with a self-assembled monolayer (SAM) prior to AuNR deposition. To date, existing studies have typically used a fixed concentration of SAM-forming organic molecules (0.2−10% v/v) while understanding how SAM density affects AuNR deposition and resulting sensing performance would be advantageous. Herein, we systematically investigated how controlling the (3-aminopropyl)triethoxysilane (APTES) concentration (1–30% v/v) during SAM preparation affects the fabrication of AuNR-coated glass surfaces for nanoplasmonic biosensing applications. Using scanning electron microscopy (SEM) and UV-visible spectroscopy, we identified an intermediate APTES concentration range that yielded the highest density of individually deposited AuNRs with minimal aggregation and also the highest peak wavelength in aqueous solution. Bulk refractive index sensitivity measurements indicated that the AuNR configuration had a strong effect on the sensing performance, and the corresponding wavelength-shift responses ranged from 125 to 290 nm per refractive index unit (RIU) depending on the APTES concentration used. Biosensing experiments involving protein detection and antigen–antibody interactions further demonstrated the high surface sensitivity of the optimized AuNR platform, especially in the low protein concentration range where the measurement shift was ~8-fold higher than that obtained with previously used sensing platforms. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) with various sizes and morphologies have been extensively investigated for effective photothermal therapy (PTT) against multiple cancer types. However, a highly dynamic and complex tumor microenvironment (TME) considerably reduces the efficacy of PTT by limiting deep tumor penetration of AuNPs. Herein, we propose a mesenchymal stem cell (MSC)-mediated deep tumor delivery of gold nanorod (AuNR) for a potent PTT. First, MSCs are treated with tetraacylated N-azidomannosamine (Ac4ManNAz) to introduce modifiable azide (N3) groups on the cell surface via metabolic glycoengineering. Then, AuNRs modified with bio-orthogonal click molecules of bicyclo[6.1.0]nonyne (AuNR@BCN) are chemically conjugated to the N3 groups on the MSC surface by copper-free click chemistry reaction, resulting in AuNR@MSCs. In cultured MSCs, the appropriate condition to incorporate the AuNR into the MSCs is optimized; in addition, the photothermal efficiency of AuNR-MSCs under light irradiation are assessed, showing efficient heat generation in vitro. In colon tumor-bearing mice, intravenously injected AuNR@MSCs efficiently accumulate within the tumor tissues by allowing deep tissue penetration owing to the tumor homing effect by natural tumor tropism of AuNR@MSCs. Upon localized light irradiation, the AuNR@MSCs significantly inhibit colon tumor growth by the enhanced photothermal effect compared to conventional AuNRs. Collectively, this study shows a promising approach of MSCs-mediated deep tumor delivery of AuNR for effective PTT. [ABSTRACT FROM AUTHOR]

Light’s orbital angular momentum (OAM) with inherent mode orthogonality has been suggested as a new way to the optical encryption. However, the dependence of annular intensity profiles on the topological charge complicates nanoscale light–matter interactions and hampers the ultra-secure encryption application. In this paper, we demonstrate ultra-secure image encryption by tightly focusing perfect optical vortex (POV) beams with controllable annular intensity profiles and OAM states. A simple scheme composed of single spatial light modulator to implement Fourier transform of an ideal Bessel mode with both amplitude and phase modulations is proposed to generate radius-controllable POV in tightly focused beams. Such focused POV beams with identical intensity profiles but varied local OAM density are applied to disorder-coupled gold nanorod aggregates to selectively excite electromagnetic hot spots for encoding information through photothermal deformation. As such, ultra-secure image encryption in OAM states of POV beams in combination with different polarizations can be achieved. Our results lay the ground for diverse nanophotonic applications harnessing the OAM division of POV beams.

The crowded intracellular environment of biomolecules, including organelles, solutes, proteins, and membranes, presents distinct biomolecular dynamics crucial for the functions of biomolecules within living cells. However, background suppression is critical to uncover nanoscale dynamics in living cells. Herein, a new method for enabling rapid, nanoscale background elimination of cellular metallic nanoprobes is presented. By employing integrated nanoscopic correction (iNC) designed to eliminate depolarization effects, which compromise background elimination, a real‐time algorithm to subtract and increment orthogonal pairs of polarizations for real‐time nanoscale background elimination is introduced. The ability to analyze orthogonal pairs at high speed over the entire polarization range is currently difficult to achieve using conventional methods. By processing orthogonal pairs in real time, this method minimizes movement artifacts during the background elimination process. Nanometer spatial stability which enables two orders of magnitude increase in signal‐to‐noise ratio of cellular metallic nanoprobes is shown. Nanoscale background elimination aiding the ability to accurately track biomolecules and their dynamics in living cells is anticipated.

The therapeutic modalities for glioblastoma multiforme fail badly due to the limitations of poor penetration through the blood–brain barrier and the lack of tumor targeting. In this study, we synthesized a neuropeptide (ANGIOPEP-2)-functionalized gold nanorod (GNR-ANGI-2) and systemically evaluated the cellular uptake and photothermal effects enhanced by the neuropeptide functionalization of the gold nanorod under laser or sham exposure. The expression of LRP1, the specific ligand for ANGIOPEP-2, was the highest in C6 cells among five studied glioma cell lines. The cellular internalization studies showed higher uptake of gold nanorods functionalized with ANGIOPEP-2 than of those functionalized with scrambled ANGIOPEP-2. The in vitro photothermal studies of C6 cells treated with GNR-ANGI-2 and laser showed a higher rate of apoptosis at early and late stages than cells treated with GNR-ANGI-2 without laser. Correspondingly, in vitro ROS evaluation showed a higher intensity of ROS production in cells treated with GNR-ANGI-2 under laser irradiation. The Western blotting results indicated that GNR-ANGI-2 with laser exposure activated the caspase pathway of apoptosis, and GNR-ANGI-2 with sham exposure induced autophagy in C6 cells. The current study provides in-depth knowledge on the effective time point for maximum cellular uptake of GNR-ANGI-2 to achieve a better anti-glioma effect. Moreover, by exploring the molecular mechanism of cell death with GNR-ANGI-2-mediated photothermal therapy, we could modify the nanoshuttle with multimodal targets to achieve more efficient anti-glioma therapy in the future. [ABSTRACT FROM AUTHOR]

Background: Cancer nanomedicines based on synthetic polypeptides have attracted much attention due to their superior biocompatibility and biodegradability, stimuli responsive capability through secondary conformation change, adjustable functionalities for various cargos such as peptides, proteins, nucleic acids and small therapeutic molecules. Recently, a few nanoformulations based on polypeptides comprising NK105, NC6004, NK911, CT2103, have entered phase I-III clinical trials for advanced solid tumors therapy. In the current study, we prepared polypeptide-based vesicles called peptosome via self-assembly of amphiphilic polypeptide-based PEG-PBLG diblock copolymer. Results: In this regard, poly(γ-benzyl L-glutamate (PBLG) was synthesized via ring opening polymerization (ROP) of γ-benzyl L-glutamate-N-carboxyanhydride (BLG-NCA) using N-hexylamine as initiator. Then amine-terminated PBLG was covalently conjugated to heterofuctional maleimide PEG-carboxylic acid or methyl-PEG-carboxylic acid. The PEG-PBLG peptosomes were prepared through double emulsion method for the co-delivery of doxorubicin.HCl and gold nanorods as hydrophilic and hydrophobic agents in interior compartment and membrane of peptosomes, respectively (Pep@MUA.GNR-DOX) that DOX encapsulation efficiency and loading capacity were determined 42 ± 3.6 and 1.68 ± 3.6. Then, theranostic peptosomes were decorated with thiol-functionalized EpCAM aptamer throught thiol-maleimide reaction producing Apt-Pep@MUA.GNR-DOX for targeted delivery. The non-targeted and targeted peptosomes showed 165.5 ± 1.1 and 185 ± 4.7 nm diameters, respectively while providing sustained, controlled release of DOX. Furthermore, non-targeted and targeted peptosomes showed considerable serum stability. In vitro study on MCF-7 and 4T1 cells showed significantly higher cytotoxicity for Apt-Pep@MUA.GNR-DOX in comparison with Pep@MUA.GNR-DOX while both system did not show any difference in cytotoxicity against CHO cell line. Furthermore, Apt-Pep@MUA.GNR-DOX illustrated higher cellular uptake toward EpCAM-overexpressing 4T1 cells compared to Pep@MUA.GNR-DOX. In preclinical stage, therapeutic and diagnostic capability of the prepared Pep@MUA.GNR-DOX and Apt-Pep@MUA.GNR-DOX were investigated implementing subcutaneous 4T1 tumor model in BALB/c mice. The obtained data indicated highest therapeutic index for Apt-Pep@MUA.GNR-DOX compared to Pep@MUA.GNR-DOX and free DOX. Moreover, the prepared system showed capability of CT imaging of tumor tissue in 4T1 tumorized mice through tumor accumulation even 24 h post-administration. Conclusion: In this regard, the synthesized theranostic peptosomes offer innovative hybrid multipurpose platform for fighting against breast cancer. [ABSTRACT FROM AUTHOR]

In this study, we developed a coarse-grained model based on the dissipative particle dynamics (DPD) method to investigate the aggregates of the cetyltrimethylammonium bromide (CTAB) molecules on gold surfaces including nanoparticles. We adopted the DPD model for CTAB solutions developed by Mao et al. [Modeling aggregation of ionic surfactants using a smeared charge approximation in dissipative particle dynamics simulations. J Phys Chem B. 2015;119:11673–11683] and introduced an attractive interaction between gold (Au) particles and bromide (Br − ) ions (i.e. Au-Br − attraction) to bind CTAB molecules onto the gold surface via the electrostatic interactions between their cationic head groups and Br − ions adsorbed on the gold surface. The proposed model with a proper Au-Br − attraction can semi-quantitatively describe the structures of CTAB aggregates on a flat gold surface and around gold nanorods (AuNRs). As the Au-Br − attraction and the CTAB concentration increase, the CTAB aggregates on the gold surface can change from micelles to a compact bilayer structure. In particular, our model predicts that in the CTAB layer, the inner sub-layer may have a higher ligand density than the outer sub-layer. The anisotropic distribution of CTAB molecules around AuNRs is also captured in our model. [ABSTRACT FROM AUTHOR]

Chemical interface damping (CID) is a recently proposed plasmon-damping pathway based on the interfacial hot-electron transfer from metal to adsorbate molecules. However, the in situ reversible tuning of CID in single gold nanorods (AuNRs) has remained a considerable challenge. In this study, we used total internal reflection scattering microscopy and spectroscopy to investigate the CID induced by p -aminoazobenzene ( p -AAB), which has fast photoisomerization characteristics, attached to single AuNRs. We demonstrated the in situ reversible tuning of CID in single AuNRs by switching between ultraviolet (UV, 365 nm) and visible (vis, 465 nm) irradiation to induce photoresponsive structural conversions between the cis and trans forms of p -AAB in ethanol, leading to different lowest unoccupied molecular orbital (LUMO) energies for both forms. The localized surface plasmon resonance (LSPR) line width was wide under vis irradiation but narrow under UV irradiation, indicating that hot electrons are more efficiently transferred to trans - p -AAB with a low LUMO energy level. We further investigated the in situ photoreversible tuning of CID by manipulating supramolecular host-guest interactions between cucurbit[8]uril (CB[8]) and p -AAB in the single AuNRs. Additionally, real-time in situ reversible tuning of CID in single AuNRs was achieved through photonic switching of the cis-trans forms of p -AAB inside CB[8]. The LSPR line width was narrow under vis irradiation but gradually widened under UV irradiation before narrowing again upon returning to vis irradiation, unlike the case with p -AAB only. These results can be ascribed to the fact that cis - p -AAB completely encapsulated within CB[8] in water is thermodynamically more favorable than trans - p -AAB. Therefore, we have discovered a new strategy for tuning the CID by performing p -AAB photoisomerization and adjusting the wavelength of incident light in single AuNRs. In addition, this study demonstrates that CID can be effectively applied to the development of biosensors to detect guest molecules and their structural changes inside the cavity of CB[8] in single AuNRs.

Gold nanorods (GNR) produce heat upon irradiation with near-infrared light, enabling a tumor-targeted photothermal therapy. In this study, we prepared GNR coated with sulfated hyaluronic acid (sHA) with a binding affinity for CD44 via electrostatic interactions to deliver GNR to tumors efficiently and stably, and evaluated their usefulness for photothermal therapy. Cationic GNR modified with trimethylammonium groups electrostatically interacted with native HA or sHA with varying degrees of sulfation to form complexes. While GNR/HA was unstable in saline, GNR/sHA maintained the absorbance peak in the near-infrared region, particularly for GNR/sHA with higher degrees of sulfation. GNR/sHA exhibited an intense photothermal effect upon irradiation with near-infrared light. Furthermore, in vitro and in vivo studies revealed that GNR coated with sHA containing approximately 1.2 sulfated groups per HA unit could accumulate in CD44-positive tumors via an HA-specific pathway. These findings indicate the effectiveness of GNR/sHA as a tumor-targeted photothermal therapeutic agent., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Photothermal imaging is useful for detecting individual nanoparticles and obtaining the absorption spectra. This study presents a wide-field photothermal reflectance spectroscopy technique achieved by incorporating a pump beam, a probe beam, and a charge-coupled device (CCD) camera into a commercial microscopic setup. The presented design does not require precise alignment between the pump and the probe beams and enables the observation of numerous individual nanoparticles during image acquisition. Despite the use of a simple imaging processing method, i.e., a four-bucket method using a CCD camera, sufficient sensitivity for the spectral imaging of a single gold nanorod (20 nm diameter and 84 nm length) is demonstrated. Numerous individual nanoparticles within a wide field of view (240 μm × 180 μm) are detected in an image captures at an imaging measurement speed of 0.02 mm2 min−1. Furthermore, the proposed photothermal reflectance spectroscopy technique can detect the variation in the absorption peak of the measured spectra depending on the aspect ratio of individual nanoparticles within a spectral resolution of 1 nm.

Abstract Chemo-photothermal therapy based on nanoparticles has emerged as a promising strategy for cancer treatment. However, its therapeutic efficacy and application potential are largely subjected to the uncontrollability and biotoxicity of functional nanoplatforms. Herein, a novel biocompatible and biodegradable metal organic framework (MOF), which was constructed by growing crystalline zeolitic imidazolate framework-8 on gold nanoroad (Au@ZIF-8), was designed and fabricated for efficient drug loading and controlled release. Owing to the large surface area and guest-matching pore size of ZIF-8, doxorubicin (DOX) was successfully loaded into the Au@ZIF-8 with a high drug loading efficiency of ~ 37%. Under NIR light or weakly acidic environment, the ZIF-8 layer was quickly degraded, which resulted in an on-demand drug release in tumour site. More importantly, under the irradiation of near infrared (NIR) laser, highly efficient cancer treatment was achieved in both in vitro cell experiment and in vivo tumour-bearing nude mice experiment due to the synergistic effect of photothermal (PTT) therapy and chemotherapy. In addition, the in vivo study revealed the good biocompatibility of Au@ZIF-8. This work robustly suggested that Au@ZIF-8 could be further explored as a drug delivery system for chemo-photothermal synergistic therapy.

The rational design of the nanocarriers with active tumor targeting and specific chemotherapy for heat shock protein 90 (Hsp90) inhibition is attractive for combined chemo-photothermal therapy (PTT). Herein, a smart gold nanorod (GNR)-cored micelle (T-GNRAAG) was developed to encapsulate 17-allylamino-17-demethoxygeldanamycin (17-AAG, Hsp90 inhibitor) through a facile preparation approach. The characteristics of T-GNRAAG were evaluated both in vitro and in vivo. The designed nanoplatform possessed sufficient 17-AAG loading content and lactobionic acid-mediated active targeting for hepatoma cells. More importantly, the 808 nm laser irradiation not only initiated PTT for cell killing but also remotely triggered 17-AAG liberation within cancer cells via inducing the phase transition of poly(ɛ-caprolactone). All these features forcefully supported the effectiveness of T-GNRAAG in tumor growth inhibition. This work represents a proof-of-concept combinatorial chemo-PTT treatment.

Controlling local and systemic factors during the wound-healing process, including inflammation, proliferation, and maturation, can play a key role in effective wound healing. It is worth taking advantage of matrix- or scaffold-based therapeutic approaches. Herein, a gold nanorod (GNR)-incorporated poly-(lactic-co-glycolic acid) (PLGA)/poly-(caprolactone) (PCL) scaffold was developed to improve the wound-healing effect by controlling heat shock protein (HSP70) via external light stimulation. The GNR-incorporated scaffold showed no harmful effects on the cells and could stimulate cell proliferation in vitro by generating mild heat generation in a timely manner with laser irradiation. A GNR-incorporated scaffold attached to the wound of mice effectively increased the local temperature to 40 °C after laser irradiation, more effectively promoting HSP70 expression and the wound-healing process compared to that of conventional dressing- and scaffold-treated mice. The GNR-incorporated scaffold and timely control HSP70 expression approach can be used as a promising wound-healing strategy for improving the therapeutic effect. [ABSTRACT FROM AUTHOR]

Solution‐processed plasmonic colloidal gold nanorods (Au NRs) are promising candidates leading to new photodetection applications. While plasmonic Au NRs of a specific dimension will lead to a well‐defined optical extinction due to the localized surface plasmon resonance, in photodetection applications broadband functioning is often desired. In this work, a broadband optical extinction is achieved from λ = 400 to 2000 nm by coupling colloidal Au NRs of various dimensions in a thin film form. Such an Au NR thin film is further applied on a platinum (Pt) electrode to fabricate hybrid Au‐NR/Pt photodetectors. On these hybrid Au‐NRs/Pt devices, thanks to the plasmonic‐induced photothermal effect, a clear broadband photoresponse is demonstrated covering the near‐infrared (NIR) and short‐wave‐infrared (SWIR) spectrum from λ = 800 to 2000 nm, with a <200 µs fast photoresponse time. This work suggests that suitably coupled plasmonic colloidal Au NRs and their strong photothermal effect are promising strategies for the future development of low‐cost and broadband NIR/SWIR photodetection. [ABSTRACT FROM AUTHOR]

Noble metal nanoparticles have been sought after in cancer nanomedicine during the past two decades, owing to the unique localized surface plasmon resonance that induces strong absorption and scattering properties of the nanoparticles. A popular application of noble metal nanoparticles is photothermal therapy, which destroys cancer cells by heat generated by laser irradiation of the nanoparticles. Gold nanorods have stood out as one of the major types of noble metal nanoparticles for photothermal therapy due to the facile tuning of their optical properties in the tissue penetrative near infrared region, strong photothermal conversion efficiency, and long blood circulation half-life after surface modification with stealthy polymers. In this review, we will summarize the optical properties of gold nanorods and their applications in photothermal therapy. We will also discuss the recent strategies to improve gold nanorod-assisted photothermal therapy through combination with chemotherapy and photodynamic therapy. [ABSTRACT FROM AUTHOR]

In this work, we studied the initiated plasmonic nanobubbles and the follow-up microbubble in gold nanorod (GNR) colloidal solution induced by a pulsed laser. Owing to the surface plasmon resonance (SPR)-enhanced photothermal effect of GNR, several nanobubbles are initiated at the beginning of illumination and then to trigger the optical breakdown of water at the focal spot of a laser beam. Consequently, microbubble generation is facilitated; the threshold of pulsed laser energy is significantly reduced for the generation of microbubbles in water with the aid of GNRs. We used a probing He-Ne laser with a photodetector and an ultrasonic transducer to measure and investigate the dynamic formations of nanobubbles and the follow-up microbubble in GNR colloids. Two wavelengths (700 nm and 980 nm) of pulsed laser beams are used to irradiate two kinds of dilute GNR colloids with different longitudinal SPRs (718 nm and 966 nm). By characterizing the optical and photoacoustic signals, three types of microbubbles are identified: a single microbubble, a coalesced microbubble of multiple microbubbles, and a splitting microbubble. The former is caused by a single breakdown, whereas the latter two are caused by discrete and series-connected multiple breakdowns, respectively. We found that the thresholds of pulsed energy to induce different types of microbubbles are reduced as the concentration of GNRs increases, particularly when the wavelength of the laser is in the near-infrared (NIR) region and close to the SPR of GNRs. This advantage of a dilute GNR colloid facilitating the laser-induced microbubble in the NIR range of the bio-optical window could make biomedical applications available. Our study may provide an insight into the relationship between plasmonic nanobubbles and the triggered microbubbles. [ABSTRACT FROM AUTHOR]

Gold nanoparticles differently affect cells depending on physical parameters (shape, size, aspect ratio, etc.). Therefore, it is essential to analyze shape- and concentration-dependent effects on cells and use them safely because new materials can simultaneously have both potential and threats. This research investigated the gold nanorod's (GNR) shape effect and the concentration criteria on cell viability and why GNR promotes cell proliferation. Unlike 10-nm and 60-nm gold nanospheres, GNR of 3.4 aspect ratio generated intracellular reactive oxygen species (ROS), and ROS affected cell viability depending on concentrations. GNRs between 0.75 pM and 37 pM produced trace ROS, which promoted HDFn (human dermal fibroblasts, neonatal) cell viability. GNRs of 7.5 nM or more produced more ROS, which reduced HDFn cell viability. On the other hand, GNRs around 0.745 nm promoted HeLa cell viability. GNRs of 3.75 nM or more repressed HeLa cell viability. Hydrogen peroxide of 0.01 and 0.1 µM promoted HDFn cell viability by 7% and 9.9%. This observation could speculate that GNR-generated ROS promoted cell proliferation via activated the ERK1/2 signaling pathway. Therefore, picomolar GNRs could be used to enhance skin cell viability in cosmetics and wound healing. On the other hand, nanomolar GNRs could be applied to kill cancer cells. [ABSTRACT FROM AUTHOR]