Search

As the number of diabetics increases yearly and diabetic ulcer is the most concerned diabetic complication, it is of great urgency to develop a novel multifunctional material with high efficiency to promote diabetic wound healing. In this paper, ceria (CeO2)‐modified upconversion nanoparticles which loaded in polycaprolactone membranes were successfully prepared as a ceria‐based wound dressing for chronic wound healing. In this system, near‐infrared (NIR) light is used as a switch to control the photodynamic antibacterial therapy by converting the NIR photons into ultraviolet light, which can further trigger CeO2 to produce reactive oxygen species. In addition, the well‐known antioxidant ability of CeO2 endows the wound dressing with prominent capability to resist the oxidative stress around chronic wounds. In summary, both photodynamic antibacterial therapy and good antioxidant property are realized simultaneously in this CeO2‐based system to promote the healing of diabetic chronic wounds. [ABSTRACT FROM AUTHOR]

Abstract As the number of diabetics increases yearly and diabetic ulcer is the most concerned diabetic complication, it is of great urgency to develop a novel multifunctional material with high efficiency to promote diabetic wound healing. In this paper, ceria (CeO2)‐modified upconversion nanoparticles which loaded in polycaprolactone membranes were successfully prepared as a ceria‐based wound dressing for chronic wound healing. In this system, near‐infrared (NIR) light is used as a switch to control the photodynamic antibacterial therapy by converting the NIR photons into ultraviolet light, which can further trigger CeO2 to produce reactive oxygen species. In addition, the well‐known antioxidant ability of CeO2 endows the wound dressing with prominent capability to resist the oxidative stress around chronic wounds. In summary, both photodynamic antibacterial therapy and good antioxidant property are realized simultaneously in this CeO2‐based system to promote the healing of diabetic chronic wounds.

Developing photoactive nanosystems against microbial infection and its therapeutic application is compromised by the lack of suitable materials or molecular dyes activatable at biofriendly NIR light. In this direction, the upconverting nanoparticles based on core–shell lanthanide‐doped nanoclusters are developed synthetically to achieve a broad range of NIR‐active phototherapeutic antimicrobial agents. This review illustrates antimicrobial photodynamic therapy (aPDT) and multimodal therapy by NIR photoirradiation, generated by lanthanum doped upconverting nanoparticles (UCNPs). The objective herein is to discuss the insights in developing the UCNPs for designing efficient aPDTs and their efficacies against emerging antibiotic‐resistant bacterial colonies and their biofilms, drug‐resistant fungi, and viruses. The biosafety and biocompatibility of UCNPs at both in vitro and in vivo level are also presented in detail. Finally, our perspectives on the ways of future material engineering needed for the effective translation into their real‐world applications are also commented. [ABSTRACT FROM AUTHOR]

• A functionalized biomimetic photoactivatable nanotherapeutics was synthesized. • Melittin was integrated into the 4T1 tumor cell membrane straightforward. • Photoactivatable nanotherapeutics released ACPT upon 808 nm irradiation. • The strategy induced the excellent antitumor immune responses. Systemically administered drugs often lead to off-target delivery, inducing compromised therapy efficacy and significant toxicity. We hypothesize that improving the drugs' targeting and spatiotemporally controllable releasing capabilities can enhance the anti-tumor effects and reduce the side effects. To achieve this goal, a functionalized biomimetic photoactivatable nanotherapeutics (U-ACPT@MM) is designed. The U-ACPT@MM comprises of melittin, a pore-forming protein, functionalized within the 4T1 tumor cell membrane, camouflaged with lanthanide-doped upconversion nanoparticles (UCNPs) conjugated with 9-aminocamptothecin (ACPT), a chemotherapeutics, by photolabile linkers. The melittin-functionalized 4T1 tumor cell membrane not only enables homologous targeting ability to 4T1 tumors, but also increases both the concentration of melittin and ACPT within tumor. Meanwhile, upon 808 nm irradiation, the UV emissions from UCNPs cut off photolabile linker to release ACPT. The synergism of enhanced tumor targeting and combinational therapeutic effects of ACPT and melittin leads to significant inhibition of 4T1 tumor and lung metastasis with reduced side effects in vivo. Thus, our study provides a promising functionalized biomimetic photoactivatable nano-therapeutical strategy for cancer therapy. [ABSTRACT FROM AUTHOR]

Certain anaerobic microbes with the capability to colonize the tumor microenvironment tend to express the heterologous gene in a sustainable manner, which will inevitably compromise the therapeutic efficacy and induce off-tumor toxicity in vivo. To improve the therapeutic precision and controllability of bacteria-based therapeutics, Escherichia coli Nissle 1917 (EcN), engineered to sense blue light and release the encoded flagellin B (flaB), is conjugated with lanthanide upconversion nanoparticles (UCNPs) for near-infrared (NIR) nano-optogenetic cancer immunotherapy. Upon 808 nm photoirradiation, UCNPs emit at the blue region to photoactivate the EcN for secretion of flaB, which subsequently binds to Toll-like receptor 5 expressed on the membrane of macrophages for activating immune response via MyD88-dependent signal pathway. Such synergism leads to significant tumor regression in different tumor models and metastatic tumors with negligible side effects. These studies based on the NIR nano-optogenetic platform highlight the rational of leveraging the optogenetic tools combined with natural propensity of certain bacteria for cancer immunotherapy., (© 2022 Wiley-VCH GmbH.)

Epitaxial growth of an inert shell around the optical active lanthanide upconversion nanoparticles (UCNPs) is a general strategy to enhance their brightness. Yet, its potential as a tool in multiplexing emission tailoring has rarely been reported. Here, by developing the atomic vacancies into color selectivity actuators, we present an efficient strategy to achieve inert-shell-modulated multiplexing upconversion in 1540 nm activated UCNPs. Artificially generated fluoride atomic vacancies, owing to the decreased NaOH/NH 4 F dosage during shell growth, reduce the coordination number of Y-F and lattice densities in the inert shell, leading to the core-engineered shell nanoparticles with distinctive emission profiles. The multicolor tailoring is independent of shell thickness and can be readily applied to Lu 3+ /Gd 3+ -based shells. The upconversion emission can be exploited to visualize in security decoding and in vivo multiplexing bioimaging. This method of regulating atomic vacancies based on the inert-shell engineering opens new insights of upconversion modulation in core-shell lanthanide nanostructures.

Peptide modification of nanoparticles with high efficiency is critical in determining the properties and bioapplications of nanoparticles, but the methodology remains a challenging task. Here, by using the phosphorylated linear and cyclic peptide with the arginine-glycine-aspartic acid (RGD) targeting motifs as typical examples, the peptides binding efficiency for the inorganic metal compound nanoparticles was increased significantly after the phosphorylation treatment, and the modification allowed for improving the selectivity and signal-to-noise ratio for cancer targeting and reduced the toxicity derived from nonspecific interactions of nanoparticles with cells owing to the higher amount of phosphopeptide binding. In addition, molecular dynamics (MD) simulations of various peptides on inorganic metal compound surfaces revealed that the peptide adsorption on the surface is mainly driven by electrostatic interactions between phosphate oxygen and the polarized interfacial water layer, consistent with the experimental observation of the strong binding propensity of phosphorylated peptides. Significantly, with the RGD phosphopeptide surface modification, these nanoparticles provide a versatile tool for tuning material-cell interactions to achieve the desired level of autophagy and may prove useful for various diagnostic and therapeutic applications.