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Solid tumors especially desmoplastic tumors are complex organ-like structures. Tumor-associated fibroblasts (TAFs), one type of the stromal cells, support the initiation, progression, and metastasis of carcinomas. TAFs also contribute to immunosuppressive tumor microenvironment (TME) and hinder T lymphocytes in killing tumors. Here, the role of TAFs in TME is discussed. In specific, TAFs form barriers for the penetration of T lymphocytes. TAFs also act as negative regulators for T lymphocytes. These findings suggest that targeting TAFs is a promising strategy for improving cancer immunotherapy. Our previous studies have indicated the ability of therapeutic nanoparticles to distribute into, and deplete or inactivate TAFs. This approach is discussed in the context of developing specific and effective immunotherapies for cancer. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Gemcitabine is widely used for anticancer therapy. However, its short blood circulation time and poor stability greatly impair its application. To solve this problem, we prepared a poly (l -glutamic acid)- g -methoxy poly (ethylene glycol)-gemcitabine conjugate (l -Gem) with a 14.3 wt% drug-loading content. l -Gem showed concentration- and time-dependent cytotoxicity towards 4T1, LLC, MIA PaCa-2 and A2780 in vitro. Pharmacokinetic and biodistribution studies indicated that l -Gem had remarkably enhanced blood stability, prolonged blood circulation time and greatly improved selective tumor distribution compared with free gemcitabine. The area under the concentration–time curve from zero to infinity [AUC (0–∞) ] of l -Gem in plasma was 43-fold higher than that of free gemcitabine. The AUC (0–∞) of the inactive metabolite, 2′-deoxy-2′,2′-difluorouridine in the l -Gem group was ∼20% of that observed in the free gemcitabine group. The drug tumor accumulation ratio in the l -Gem group relative to the free gemcitabine group was 9.9 at 36 h, while the tumor AUC ratio was 15.8. Testing on Balb/C mice bearing the 4T1 tumor further demonstrated that l -Gem had significantly higher anticancer efficacy than free gemcitabine in vivo. These findings indicated that l -Gem has great potential for cancer treatment. [ABSTRACT FROM AUTHOR]

Abstract: For most cancer types, only a minority of cancer patients respond to checkpoint inhibition therapy. T lymphocyte infiltration is critically important for checkpoint blockade immunotherapy. High expression of high mobility group protein A1 (HMGA1) is observed in rapidly proliferating neoplastic cells, and is reported to contribute to the immunosuppressive microenvironment in the tumor. Herein, whether the silencing of HMGA1 using a nanoparticle (NP) approach could promote T lymphocyte infiltration into the tumor, and sensitize tumors to checkpoint inhibitor therapy in several orthotopic murine cancer models, which has high levels of HMGA1 but little T lymphocyte infiltration, is investigated. Selectively silencing HMGA1 using a lipid‐protamine‐hyaluronic acid‐siHMGA1 (LPH‐siHMGA1) NP system greatly enhances the lymphocyte infiltration in the tumor. Furthermore, the combination of LPH‐siHMGA1 and a locally expressed PD‐L1 inhibitor system, a lipid‐protamine‐DNA NP loaded with plasmid encoding the PD‐L1 trap fusion protein, significantly inhibits the tumor growth and prolonged survival. LPH‐siHMGA1 also decreased the content of stem cells in the tumor. These findings highlight the potential of targeting HMGA1, especially using a nano approach, in the combination with cancer immunotherapy, and provide a strategy for broadening the application and enhancing the efficacy of checkpoint inhibitors. [ABSTRACT FROM AUTHOR]

Cancer immunotherapy is quickly growing to be the fourth most important cancer therapy, after surgery, radiation therapy, and chemotherapy. Immunotherapy is the most promising cancer management strategy because it orchestrates the body’s own immune system to target and eradicate cancer cells, which may result in durable antitumor responses and reduce metastasis and recurrence more than traditional treatments. Nanomaterials hold great promise in further improving the efficiency of cancer immunotherapy - in many cases, they are even necessary for effective delivery. In this review, we briefly summarize the basic principles of cancer immunotherapy and explain why and where to apply nanomaterials in cancer immunotherapy, with special emphasis on cancer vaccines and tumor microenvironment modulation. [ABSTRACT FROM AUTHOR]

A poly( l -glutamic acid) graft polyethylene glycol-cisplatin complex (PGA-CisPt) performs well in reducing the toxicity of free cisplatin and greatly enhances the accumulation and retention of cisplatin in solid tumors. However, there is a lack of effective treatment options for cisplatin-resistant tumors. A major reason for this is the dense PEG shell, which ensures that the PGA-CisPt maintains a long retention time in the blood that may result in it bypassing the tumor cells or failing to be endocytosed within the tumor microenvironment. Consequently, the cisplatin from PGA-CisPt is released to the extracellular space in the presence of cisplatin-resistant tumor cells and the resistant problem to free cisplatin still valid. Therefore, we devised a strategy to combat the resistance of cisplatin in the tumor microenvironment using nanoparticles-loaded disulfiram (NPs-DSF) as a modulator. In vitro , cisplatin, in combination with DSF, had a synergistic effect and decreased cell survival rate of cisplatin-resistant A549DDP cells. This effect was also observed when combining PGA-CisPt with NPs-DSF. Similarly, in Balb/C nude mice with A549DDP xenografts, NPs-DSF improved PGA-CisPt effectiveness in inhibiting tumor growth while maintaining low toxicity. Our data demonstrate that DSF reduces intracellular glutathione (GSH) levels, inhibits NFκB activity, and modulates the expression of apoptosis-related proteins Bcl-2 and Bax, thereby improves the effectiveness of cisplatin in resistant cell lines. Here, we provide a promising method for overcoming cisplatin resistance in tumors, while maintaining the in vivo benefits of the PGA-CisPt complex. [ABSTRACT FROM AUTHOR]

Abstract: There are two important obstacles for the currently applied anti-cancer drug delivery systems. One is the conflict between long-circulation and cellular uptake while the other one is the achievement of ideal anti-cancer efficacy. To solve these problems, we designed a polypeptide-based micelle system that combined the advantages of receptor mediated endocytosis and multi-drug delivery. Firstly, an amphiphilic PLG-g-Ve/PEG graft copolymer was prepared by grafting α-tocopherol (Ve) and polyethylene glycol (PEG) to poly(l-glutamic acid) (PLG). Then docetaxel (DTX) and cisplatin (CDDP) were co-loaded into the PLG-g-Ve/PEG micelles via hydrophobic and chelation effect. After that, the surface of the dual-drug-loaded micelles was decorated with an αvβ3 integrin targeting peptide c(RGDfK). The targeted dual-drug-loaded micelles showed synergistic cytotoxicity and enhanced internalization rate in mouse melanoma (B16F1) cells. In vivo tests demonstrated that remarkable long circulation, anti-tumor and anti-metastasis efficacy could be achieved using this drug delivery system. This work revealed a strategy for the design and preparation of anti-cancer drug delivery systems with reduced side effect, enhanced anti-tumor and anti-metastasis efficacy. [Copyright &y& Elsevier]

Abstract: Construction of high density glycosylated surfaces is important in the investigation of interactions between pathogens and surface carbohydrates. In this work, we provided a flexible method for glycosyl surface fabrication by combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction. Through this strategy, we got a very high surface glycosyl density of about 4nmol/cm2 with the surface “click” efficiency of nearly 50%. Then the carbohydrate decorated surfaces were used to mimic cell surfaces and specific recognition of mannose with Escherichia coli was observed. We believe the methodology provided here can be used as a facile way for construction of a wide range of functional biosurfaces. [Copyright &y& Elsevier]

Reversing the aggravated immunosuppression hence overgrowth of colorectal cancer (CRC) caused by the gut inflammation and microbiota dysbiosis is pivotal for effective CRC therapy and metastasis inhibition. However, the low delivery efficiency and severe dose-limiting off-target toxicities caused by unsatisfied drug delivery systems remain the major obstacles in precisely modulating gut inflammation and microbiota in CRC therapy. Herein, a multifunctional oral dextran-aspirin nanomedicine (P3C-Asp) was utilized for oral treatment of primary CRC, as it could release salicylic acid (SA) while scavenging reactive oxygen species (ROS) and held great potential in modulating gut microbiota with prebiotic (dextran). Oral P3C-Asp retained in CRC tissues for over 12 h and significantly increased SA accumulation in CRC tissues over free aspirin (10.8-fold at 24 h). The enhanced SA accumulation and ROS scavenging of P3C-Asp cooperatively induced more potent inflammation relief over free aspirin, characterized as lower level of cyclooxygenase-2 and immunosuppressive cytokines. Remarkably, P3C-Asp promoted the microbiota homeostasis and notably increased the relative abundance of strengthening systemic anti-cancer immune response associated microbiota, especially lactobacillus and Akkermansia to 6.66- and 103- fold over the control group. Additionally, a demonstrable reduction in pathogens associated microbiota (among 96% to 79%) including Bacteroides could be detected. In line with our findings, inflammation relief along with enhanced abundance of lactobacillus was positively correlated with CRC inhibition. In primary CRC model, P3C-Asp achieved 2.1-fold tumor suppression rate over free aspirin, with an overall tumor suppression rate of 85%. Moreover, P3C-Asp cooperated with αPD-L1 further reduced the tumor weight of each mouse and extended the median survival of mice by 29 days over αPD-L1 alone. This study unravels the synergistic effect of gut inflammation and microbiota modulation in primary CRC treatment, and unlocks an unconventional route for immune regulation in TME with oral nanomedicine. [Display omitted] • P3C-Asp is constructed with aspirin, ROS scavenging moiety, and prebiotic for primary colorectal cancer treatment. • P3C-Asp can simultaneously improve tumor microenvironment and enhance probiotics to reinvigorate antitumor immune responses. • The noninvasive and functional-rich P3C-Asp provides a promising candidate for gastrointestinal diseases treatment. [ABSTRACT FROM AUTHOR]

Tumor is known as "a wound that does not heal". Tumor-promoting inflammation plays a crucial role in carcinogenesis, tumor progression, tumor metastasis, as well as chemotherapy resistance. Therefore, reducing tumor-promoting inflammation may be a key aspect in targeting the tumor microenvironment for cancer therapy. Dexamethasone (DEX), a commercial drug in the treatment of many different inflammatory diseases, can effectively inhibit the release of substances causing inflammation. However, as a corticosteroid medication, direct use of DEX results in many severe side effects. In this study, a redox and pH dual sensitive polypeptide-DEX conjugate (L–SS–DEX) was synthesized, and the L–SS–DEX dramatically increased the tumoral accumulation of DEX in murine colorectal cancer model (CT26) compared to free DEX. Importantly, at equal dose (10 mg/kg), L–SS–DEX showed superior antitumor activity over free DEX: 86% tumor suppression rate of L–SS–DEX treatment group compared to 49% of free DEX treatment group. Further analysis of the tumor tissues showed that cyclooxygenase-2 (COX-2) and α-smooth muscle actin (α-SMA) were significantly reduced after the L–SS–DEX treatment compared with control groups. In addition, the immunosuppressive microenvironment of the CT26 tumor was effectively relieved after L–SS–DEX treatment, characterized by increased CD8+ T cell infiltration, increased ratio of M1 over M2 macrophages, as well as markedly decrease in regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). The above results suggest that anti-inflammatory drugs hold great potential in modulating the tumor microenvironment when delivered properly, and can also result in significant tumor inhibition effects. Since dramatic amounts of anti-inflammatory drugs have been used in clinic, our results may provide improved tumor therapy options of using anti-inflammatory drugs for cancer therapy. Image 1 [ABSTRACT FROM AUTHOR]

A hit-and-run vaccine system, with POx-Hmi/OVA nanovaccine firstly elicit OVA257-264 specific T cell responses, and then PMEBOx-MMP-OVA specifically deliver OVA257-264 peptides to decorate the tumor cell surface, thus results in T cell killing to tumor cells regardless the original surface epitopes. [Display omitted] Neoantigen cancer vaccines have been envisioned as one of the most promising means for cancer therapies. However, identifying neoantigens for tumor types with low tumor mutation burdens continues to limit the effectiveness of neoantigen vaccines. Herein, we proposed a "hit-and-run" vaccine strategy which primes T cells to attack tumor cells decorated with exogenous "neo-antigens". This vaccine strategy utilizes a peptide nanovaccine to elicit antigen-specific T cell responses after tumor-specific decoration with a nanocarrier containing the same peptide antigens. We demonstrated that a poly(2-oxazoline)s (POx) conjugated with OVA 257-264 peptide through a matrix metalloprotease 2 (MMP-2) sensitive linker could efficiently and selectively decorate tumor cells with OVA peptides in vivo. Then, a POx-based nanovaccine containing OVA 257-264 peptides to elicit OVA-specific T cell responses was designed. In combination with this hit-and-run vaccine system, an effective vaccine therapy was demonstrated across tumor types even without OVA antigen expression. This approach provides a promising and uniform vaccine strategy against tumors with a low tumor mutation burden. [ABSTRACT FROM AUTHOR]

Virus-like particle (VLP) vaccines had shown great potential during the COVID-19 pandemic, and was thought to be the next generation of antiviral vaccine technology due to viromimetic structures. However, the time-consuming and complicated processes in establishing a current recombinant-protein–based VLP vaccine has limited its quick launch to the out-bursting pandemic. To simplify and optimize VLP vaccine design, we herein report a kind of viromimetic polymer nanoparticle vaccine (VPNVax), with subunit receptor-binding domain (RBD) proteins conjugated to the surface of polyethylene glycol- b -polylactic acid (PEG- b -PLA) nanoparticles for vaccination against SARS-CoV-2. The preparation of VPNVax based on synthetic polymer particle and chemical post-conjugation makes it possible to rapidly replace the antigens and construct matched vaccines at the emergence of different viruses. Using this modular preparation system, we identified that VPNVax with surface protein coverage of 20%–25% had the best immunostimulatory activity, which could keep high levels of specific antibody titers over 5 months and induce virus neutralizing activity when combined with an aluminum adjuvant. Moreover, the polymer nano-vectors could be armed with more immune-adjuvant functions by loading immunostimulant agents or chemical chirality design. This VPNVax platform provides a novel kind of rapidly producing and efficient vaccine against different variants of SARS-CoV-2 as well as other viral pandemics. [ABSTRACT FROM AUTHOR]

Immunotherapy has been widely used in the treatment of advanced stage cancers with spreading metastases, while the fully activation of immune system often requires sustained and long-acting immune stimulation by immunotherapeutic agents. In previous studies, we designed a biopolymer immune implant by dynamic covalent bonds and achieved sustained release of loaded immunotherapeutic agents, thus stimulated systemic immune activation and elicited immune memory effects. Herein, we further optimized the implants and carried out a comprehensive evaluation of the implants on peritoneal metastasis carcinoma (PMC) therapy. Our results showed that the implants fabricated with 8-arm polyethylene glycol amine (8-arm PEG-NH 2) and 40% oxidation degree dextran (ODEX) exhibited a satisfactory degradation time for activating the antitumor immunity. The drug combination of oxaliplatin (OxP) and resiquimod (R848) could be sustainably released from the implants for 18 days. The implants cured 75% of mice with PMC and elicited immune memory effects to resist tumor re-challenge without obvious side effects observed. Mechanism analysis revealed that the implants could serve as an in-situ vaccine to enhance the infiltration of activated dendritic cells (DCs), T cells and natural killer (NK) cells inside the tumor, as well as increase the serum tumor necrosis factor α (TNF-α), interferon-γ (IFN-γ) and interleukin 12 (IL-12) levels. These results strongly support the clinical translation potential of this sustained released biopolymer immune implants for PMC therapy. [Display omitted] • Lasting immune stimulation was vital for the activation of antitumor immunity and the establishment of immune memory effect. • The combination of oxaliplatin, imiquimod and aPD-1 was necessary for peritoneal metastasis carcinoma therapy. • The therapeutic results of immune implants elucidate the promise of the biopolymer immune implant for clinical translation. [ABSTRACT FROM AUTHOR]

Interactions between different cell types in the tumor microenvironment (TME) affect tumor growth. Tumor-associated fibroblasts produce C-X-C motif chemokine ligand 13 (CXCL13) which recruits B cells to the TME. B-cells in the TME differentiate into regulatory B cells (Bregs) (IL-10+CD1d+CD5+CD138+CD19+). We highlight these Breg cells as a new important factor in the modulation of the immunosuppressive TME in different desmoplastic murine tumor models. In addition, CXCL13 also stimulates epithelial–mesenchymal transition (EMT) of the tumor cells. The tumorigenic roles of CXCL13 led us to explore an innovative anti-cancer strategy based on delivering plasmid DNA encoding a CXCL13 trap to reduce Bregs differentiation and normalize EMT, thereby suppressing tumor growth. CXCL13 trap suppressed tumor growth in pancreatic cancer, BRAF-mutant melanoma, and triple-negative breast cancer. In this study, following treatment, the affected tumor remained dormant resulting in prolonged progression-free survival of the host. [Display omitted] • Chemokine CXCL13 recruits B cells to the tumor microenvironment (TME), where they differentiate into regulatory B cells (Bregs). • We highlight these Breg cells as a new key element in controlling the immunosuppressive TME in different desmoplastic murine tumor models. • The tumorigenic roles of CXCL13 led us to explore an innovative anti-cancer strategy trap to reduce Bregs differentiation and normalize EMT. [ABSTRACT FROM AUTHOR]

As the most common malignancy in women, breast cancer causes >40,000 deaths annually. Ribonuclease A (RNase), a new anti-cancer agent, has attracted intense interest due to its high efficacy and specificity. However, RNase suffers from instability, a short half-life in the circulation and poor membrane penetration. To overcome these challenges, we designed a supramolecular nanogel for the cytosolic delivery of RNase. The nanogels were fabricated using host–guest interactions between azobenzene (Azo) and β-cyclodextrin (βCD) conjugated to poly (L-glutamic acid)- graft -poly (ethylene glycol) methyl ether (PLG- g -mPEG). RNase could be loaded inside the nanogels in mild aqueous conditions. Following optimization, the RNase-loading content and efficiency of the nanogel were 23.5 wt% and 50.4%, respectively. In the presence of nitroreductase (NTR), the cross-linking point between Azo and βCD was destroyed due to the conformation transition of Azo, ensuring the hypoxia-sensitive release of cargo from the nanogels in tumors in which NTR is overexpressed. In vitro release profiles revealed that 75.0% of the RNase was released under hypoxic conditions in 72 h, whilst only 19.7% was released under normoxic conditions. Cytotoxicity assays showed that the RNase-loaded nanogels (nano-RNase) were more efficient in inhibiting the proliferation of 4T1 cells than free RNase. In vivo studies showed 68.7% tumor suppression rates (TSR %) in the nano-RNase treated group, whilst free RNase treatment led to a lack of tumor inhibition. To further enhance the hypoxia status of tumors, we combined nano-RNase with a nanoformulation of vascular disrupting agents PLG- g -mPEG/combretastatinA4 (nano-CA4) and obtained a TSR of 91.7%. The hypoxia-sensitive supramolecular nanogels provided a versatile platform for the delivery of RNase, highlighting its applicability for cancer therapy. Unlabelled Image • Supramolecular nanogels were fabricated using host–guest interactions between azobenzene and β-cyclodextrin. • Protein could be loaded inside the nanogels in mild aqueous conditions though a direct mixing method. • RNase could release from nanogels in hypoxia, suggesting the potential for tumor-selective drug delivery. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Platinum drugs comprise of almost 50% of all currently used anticancer drugs. They are now widely used in the clinical therapy of various solid tumors, including ovarian, head and neck, colorectal, lung cancers, and so forth. However, their extensive systemic toxicity and the drug resistance acquired by cancer cells limit the applications of platinum drugs. Modern nanobiotechnology provides the possibility for targeted delivery of platinum drugs to the tumor site, thereby minimizing toxicity and optimizing the efficacies of the drugs. Numerous drug delivery carriers, such as polymer nanoparticles, solid lipids, and inorganic nanoparticles, have been developed over the years for delivering platinum drugs. Thus, significant improvements have been made in this field, especially for polymer-based platinum drug delivery systems. In the past five years, particularly interesting studies have been done regarding polymer-based carriers for platinum(IV) drugs, which are chemically inert but can be activated either by intracellular glutathione (GSH) and ascorbic acid (chemically reductive platinum(IV) drugs) or by ultraviolet (UV)/green light (photosensitive platinum(IV) drugs). This review presents a comprehensive overview on the development of various types of polymer-based platinum drug delivery systems. It spans both single-drug carriers and carriers that are combined with other imaging agents, drug sensitizers, and anticancer drugs. Their fabrication methods, mechanisms of action, their applications in cancer therapy, as well as the prospect of their development in the future are also predicted. [ABSTRACT FROM AUTHOR]

Using nanotechnology for cancer vaccine design holds great promise because of the intrinsic feature of nanoparticles in being captured by antigen-presenting cells (APCs). However, there are still obstacles in current nanovaccine systems in achieving efficient tumor therapeutic effects, which could partially be attributed to the unsatisfactory vaccine carrier design. Herein, we report a mannan-decorated pathogen-like polymeric nanoparticle as a protein vaccine carrier for eliciting robust anticancer immunity. This nanovaccine was constructed as a core-shell structure with mannan as the shell, polylactic acid-polyethylenimine (PLA-PEI) assembled nanoparticle as the core, and protein antigens and Toll-like receptor 9 (TLR9) agonist CpG absorbed onto the PLA-PEI core via electrostatic interactions. Compared to other hydrophilic materials, mannan decoration could greatly enhance the lymph node draining ability of the nanovaccine and promote the capturing by the CD8+ dendritic cells (DCs) in the lymph node, while PLA-PEI as the inner core could enhance antigen endosome escape thus promoting the antigen cross-presentation. In addition, mannan itself as a TLR4 agonist could synergize with CpG for maximally activating the DCs. Excitingly, we observed in several murine tumor models that using this nanovaccine alone could elicit robust immune response in vivo and result in superior anti-tumor effects with 50% of mice completely cured. This study strongly evidenced that mannan decoration and a rationally designed nanovaccine system could be quite robust in tumor vaccine therapy. [ABSTRACT FROM AUTHOR]

Platinum-based polymeric nano-drugs, especially cisplatin-loaded polymeric nanoparticles (CDDP-NPs), have been extensively exploited for the treatment of solid tumors. However, it is still unclear what role the processing procedure and the properties of the polymeric carrier materials may play in influencing the plasma pharmacokinetics, biodistribution and in vivo efficacy of CDDP-NPs. In this study, a series of poly( l -glutamic acid)- g -methoxy poly(ethylene glycol) (PLG- g -mPEG) copolymers were synthesized for the preparation of CDDP-loaded PLG- g -mPEG (CDDP/PLG- g -mPEG) nanoparticles. All of the parameters, including PLG molecular weight, mPEG/PLG weight ratio, mPEG chain length, ultrafiltration purification and cisplatin loading content, were found to have a significant influence on the plasma pharmacokinetics of the CDDP/PLG- g -mPEG nanoparticles. The blood circulation time of the nanoparticles was prolonged with increases in PLG molecular weight, mPEG/PLG weight ratio, mPEG chain length and CDDP loading content. The use of ultrafiltration purification could prolong the blood circulation time of the nanoparticles as well. Experiments to measure the pharmacokinetics and biodistribution demonstrated that the selected CDDP/PLG- g -mPEG nanoparticles, NP10, had a long blood circulation time and could achieve selective and significant accumulation in Lewis lung carcinoma (LLC) tumors. The platinum plasma concentrations in the LLC tumor-bearing mice receiving NP10 remained up to 46-fold higher than that of mice receiving equivalent doses of free CDDP. In addition, the plasma area under the concentration time curve (AUC) of NP10 was 31-fold higher than that of free CDDP in 48 h. The platinum concentration ratio of NP10 to free CDDP in tumors reached as high as 9.4. The tumor AUC ratio of NP10 to CDDP was 6. Using a mouse C26 tumor model, here we demonstrate that NP10 improves the safety and tolerance in vivo when compared to CDDP and effectively inhibits the growth of C26 tumors. Furthermore, increasing the dosage of NP10 by 2 or 3-fold of free CCDP improved its anticancer efficacy to comparable or higher levels. These results indicate that CDDP/PLG- g -mPEG nanoparticles have greater potential for the treatment of solid tumors in clinical application. [ABSTRACT FROM AUTHOR]

The synthesis of polymer–drug conjugate (PDC) capable of convenient preparation and controlled release of therapeutic agents is still an urgent requirement in drug delivery field. Herein, we develop a novel anti-cancer PDC engineered with side groups of disulfide and ester bonds for on-demand delivery of paclitaxel (PTX) with redox and pH dual sensitive behaviors. A simple polymer, 3,3′-dithiodipropionic acid functionalized poly(ethylene glycol)- b -poly( l -lysine) (mPEG- b -P(LL-DTPA)), was synthesized and PTX was directly conjugated to the carboxyl groups of mPEG- b -P(LL-DTPA) to obtain the disulfide-containing polymer–PTX conjugate (P(L-SS-PTX)). Another structural similar polymer–PTX conjugate without disulfide bonds (P(L-PTX)) was also prepared to verify the function of disulfide linkages. The P(L-SS-PTX) micelles showed rapid drug release under tumor-relevant reductive conditions as designed. Interestingly, the PTX release from P(L-SS-PTX) micelles could also be promoted by the increased acidity (pH ≈ 5). In vitro cytotoxicity study showed that the P(L-SS-PTX) micelles exhibited significantly enhanced cytotoxicity against a variety of tumor cells compared to the non-sensitive P(L-PTX) micelles. The in vivo studies on B16F1 melanoma bearing C57BL/6 mice demonstrated the superior antitumor activity of P(L-SS-PTX) over both free PTX and P(L-PTX). This dual-sensitive prodrug provides a useful strategy for anti-tumor drug delivery. [ABSTRACT FROM AUTHOR]

Abstract: Despite progress, combination therapy of different functional drugs to increase the efficiency of anticancer treatment still remains challenges. An amphiphilic methoxy poly(ethylene glycol)-b-poly(l-glutamic acid)-b-poly(l-lysine) triblock copolymer decorated with deoxycholate (mPEsG-b-PLG-b-PLL/DOCA) was synthesized and developed as a nanovehicle for the co-delivery of anticancer drugs: doxorubicin (DOX) and paclitaxel (PTX). The amphiphilic copolymer spontaneously self-assembled into micellar-type nanoparticles in aqueous solutions and the blank nanoparticles possessed excellent stability. Three different domains of the copolymer performed distinct functions: PEG outer corona provided prolonged circulation, middle biodegradable and hydrophilic PLG shell was designed for DOX loading through electrostatic interactions, and hydrophobic deoxycholate modified PLL served as the container for PTX. In vitro cytotoxicity assays against A549 human lung adenocarcinoma cell line demonstrated that the DOX + PTX co-delivered nanoparticles (Co-NPs) exhibited synergistic effect in inducing cancer cell apoptosis. Ex vivo DOX fluorescence imaging revealed that Co-NPs had highly efficient targeting and accumulation at the implanted site of A549 xenograft tumor in vivo. Co-NPs exhibited significantly higher antitumor efficiency in reducing tumor size compared to free drug combination or single drug-loaded nanoparticles, while no obvious side effects were observed during the treatment, indicating this co-delivery system with different functional antitumor drugs provides the clinical potential in cancer therapy. [Copyright &y& Elsevier]

Abstract: pH responsive cisplatin prodrug crosslinked polysaccharide-based nanoparticles were developed from succinic acid decorated dextran (Dex-SA) for active loading and triggered intracellular release of doxorubicin (DOX). Nanoparticles with uniform size were formed spontaneously in aqueous medium via electrostatic interaction between anionic Dex-SA and cationic DOX, and subsequently transformed into crosslinked nanoparticles (CL-Nanoparticles) in situ by readily crosslinking the micelles via chelate interactions between the ionic polymeric carrier and the platinum (II) antitumor drug. This strategy eliminated the need of organic solvents and sophisticated processes in the drug loading procedure. The in vitro release studies showed that DOX was released from the CL-Nanoparticles in a controlled and pH-dependent manner. Furthermore, the pharmacokinetics and biodistribution investigations indicated that, as compared to the non-crosslinked nanoparticles (NCL-Nanoparticles) and free DOX, the CL-Nanoparticles significantly prolonged the blood circulation time of drug, decreased accumulation in the normal tissues and enriched drug into the tumors. As a consequence, the DOX-loaded CL-Nanoparticles exhibited enhanced therapeutic efficacy in tumor-bearing mice compared with the NCL-Nanoparticles and free DOX, which were further confirmed by the histological and immunohistochemical analyses. These cisplatin prodrug crosslinked polysaccharide nanoparticles proved to be a promising nanomedicine drug delivery system for tumor-targeted delivery of DOX. [Copyright &y& Elsevier]

[Display omitted] Traditional herbal medicine (THM), an ancient science, is a gift from nature. For thousands of years, it has helped humans fight diseases and protect life, health, and reproduction. Nanomedicine, a newer discipline has evolved from exploitation of the unique nanoscale morphology and is widely used in diagnosis, imaging, drug delivery, and other biomedical fields. Although THM and nanomedicine differ greatly in time span and discipline dimensions, they are closely related and are even evolving toward integration and convergence. This review begins with the history and latest research progress of THM and nanomedicine, expounding their respective developmental trajectory. It then discusses the overlapping connectivity and relevance of the two fields, including nanoaggregates generated in herbal medicine decoctions, the application of nanotechnology in the delivery and treatment of natural active ingredients, and the influence of physiological regulatory capability of THM on the in vivo fate of nanoparticles. Finally, future development trends, challenges, and research directions are discussed. [ABSTRACT FROM AUTHOR]

STING (stimulator of interferon genes) signaling pathway has attracted considerable attention in cancer immunotherapy due to its capacity to boost vigorous antitumor immunity. However, the shortage of effective STING agonists limits the promotion of STING pathway in cancer treatment. Herein, we present an approach for in situ activation of STING pathway with nanoparticles delivered DNA-targeting chemo agents, based on the understanding that cytosol DNA is a pre-requisite for STING pathway activation. Through in vitro screening among several DNA-targeting chemo agents, we identified 7-ethyl-10-hydroxycamptothecin (SN38) as the most potent drug for stimulating interferon (IFN)-β secretion and proved that this process is mediated by the passage of DNA-containing exosomes from treated tumor cells to bone marrow-derived dendritic cells (BMDCs) and subsequent activation of the STING pathway. Furthermore, we designed a polymeric-SN38 conjugate that could self-assemble into nanoparticles (SN38-NPs) for in vivo application. The SN38-NPs formulation reduced toxicity of free SN38, effectively stimulated the activation of STING pathway in E0771 tumors, and resulted in a tumor suppression rate (TSR%) of 82.6%. Our results revealed a new mechanism of SN38 in cancer treatment and should inspire using more DNA-targeting agents, especially in nanoformulation, for activating STING pathway and cancer chemoimmunotherapy. Image 1 [ABSTRACT FROM AUTHOR]

Immunotherapy has emerged as an effective strategy for the prevention and treatment of a variety of diseases, including cancer, infectious diseases, inflammatory diseases, and autoimmune diseases. Immunomodulatory nanosystems can readily improve the therapeutic effects and simultaneously overcome many obstacles facing the treatment method, such as inadequate immune stimulation, off‐target side effects, and bioactivity loss of immune agents during circulation. In recent years, researchers have continuously developed nanomaterials with new structures, properties, and functions. This Review provides the most recent advances of nanotechnology for immunostimulation and immunosuppression. In cancer immunotherapy, nanosystems play an essential role in immune cell activation and tumor microenvironment modulation, as well as combination with other antitumor approaches. In infectious diseases, many encouraging outcomes from using nanomaterial vaccines against viral and bacterial infections have been reported. In addition, nanoparticles also potentiate the effects of immunosuppressive immune cells for the treatment of inflammatory and autoimmune diseases. Finally, the challenges and prospects of applying nanotechnology to modulate immunotherapy are discussed. [ABSTRACT FROM AUTHOR]