Glutathione-Responsive and Hydrogen Sulfide Self-Generating Nanocages Based on Self-Weaving Technology To Optimize Cancer Immunotherapy.

As an ideal drug carrier, it should possess high drug loading and encapsulation efficiency and precise drug targeting release. Herein, we utilized a template-guided self-weaving technology of phase-separated silk fibroin (SF) in reverse microemulsion (RME) to fabricate a kind of hyaluronic acid (HA) coated SF nanocage (HA-gNCs) for drug delivery of cancer immunotherapy. Due to the hollow structure, HA-gNCs were capable of simultaneous encapsulation of the anti-inflammatory drug betamethasone phosphate (BetP) and the immune checkpoint blockade (ICB) agent PD-L1 antibody (αPD-L1) efficiently. Another point worth noting was that the thiocarbonate cross-linkers used to strengthen the SF shell of HA-gNCs could be quickly broken by overexpressed glutathione (GSH) to reach responsive drug release inside tumor tissues accompanied by hydrogen sulfide (H2S) production in one step. The synergistic effect of released BetP and generated H2S guaranteed chronological modulation of the immunosuppressive tumor microenvironment (ITME) to amplify the therapeutic effect of αPD-L1 for the growth, metastasis, and recurrence of tumors. This study highlighted the exceptional prospect of HA-gNCs as a self-assistance platform for cancer drug delivery.

Gut Clostridium sporogenes-derived indole propionic acid suppresses osteoclast formation by activating pregnane X receptor.

Bone homeostasis is maintained by osteoclast-mediated bone resorption and osteoblast-mediated bone formation. A dramatic decrease in estrogen levels in postmenopausal women leads to osteoclast overactivation, impaired bone homeostasis, and subsequent bone loss. Changes in the gut microbiome affect bone mineral density. However, the role of the gut microbiome in estrogen deficiency-induced bone loss and its underlying mechanism remain unknown. In this study, we found that the abundance of Clostridium sporogenes (C. spor.) and its derived metabolite, indole propionic acid (IPA), were decreased in ovariectomized (OVX) mice. In vitro assays suggested that IPA suppressed osteoclast differentiation and function. At the molecular level, IPA suppressed receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced pregnane X receptor (PXR) ubiquitination and degradation, leading to increased binding of remaining PXR with P65. In vivo daily IPA administration or repeated C. spor. colonization protected against OVX-induced bone loss. To protect live bacteria from the harsh gastric environment and delay the emptying of orally administered C. spor. from the intestine, a C. spor.-encapsulated silk fibroin (SF) hydrogel system was developed, which achieved bone protection in OVX mice comparable to that achieved with repeated germ transplantation or daily IPA administration. Overall, we found that gut C. spor.-derived IPA was involved in estrogen deficiency-induced osteoclast overactivation by regulating the PXR/P65 complex. The C. spor.-encapsulated SF hydrogel system is a promising tool for combating postmenopausal osteoporosis without the disadvantages of repeated germ transplantation.

Transient Mild Photothermia Improves Therapeutic Performance of Oral Nanomedicines with Enhanced Accumulation in the Colitis Mucosa.

The treatment outcomes of oral medications against ulcerative colitis (UC) have long been restricted by low drug accumulation in the colitis mucosa and subsequent unsatisfactory therapeutic efficacy. Here, high-performance pluronic F127 (P127)-modified gold shell (AuS)-polymeric core nanotherapeutics loading with curcumin (CUR) is constructed. Under near-infrared irradiation, the resultant P127-AuS@CURs generate transient mild photothermia (TMP; ≈42 °C, 10 min), which facilitates their penetration through colonic mucus and favors multiple cellular processes, including cell internalization, lysosomal escape, and controlled CUR release. This strategy relieves intracellular oxidative stress, improves wound healing, and reduces immune responses by polarizing the proinflammatory M1-type macrophages to the anti-inflammatory M2-type. Upon oral administration of hydrogel-encapsulating P127-AuS@CURs plus intestinal intralumen TMP, their therapeutic effects against acute and chronic UC are demonstrated to be superior to those of a widely used clinical drug, dexamethasone. The treatment of P127-AuS@CURs (+ TMP) elevates the proportions of beneficial bacteria (e.g., Lactobacillus and Lachnospiraceae), whose metabolites can also mitigate colitis symptoms by regulating genes associated with antioxidation, anti-inflammation, and wound healing. Overall, the intestinal intralumen TMP offers a promising approach to enhance the therapeutic outcomes of noninvasive medicines against UC.

Non-Pore Dependent and MMP-9 Responsive Gelatin/Silk Fibroin Composite Microparticles as Universal Delivery Platform for Inhaled Treatment of Lung Cancer.

Developing a drug delivery platform that possesses universal drug loading capacity to meet various requirements of cancer treatment is a challenging yet interesting task. Herein, a self-assembled gelatin/silk fibroin composite (GSC) particle based drug delivery system is developed via microphase separation followed by desolvation process. Thanks to its preassembled microphase stage, this GSC system is suitable for varying types of drugs. The desolvation process fix drugs inside GSC rapidly and densify the GSC structure, thereby achieving efficient drug loading and providing comprehensive protection for loaded drugs. Actually, the size of this brand-new non-pore dependent drug delivery system can be easily adjusted from 100 nm to 20 µm to fit different scenarios. This work selects GSC with 3 µm diameter as the universal inhaled drug delivery platform, which shows an excellent transmucosal penetration and lung retention ability. Additionally, the MMP-9 sensitive degradation property of GSC enhances the targeted efficiency of drugs and reduces side effects. Intestinally, GSC can self-amplify the regulation of innate immunity to reverse the cancerous microenvironment into an antitumor niche, significantly improving the therapeutic effect of drugs. This study of GSC universal drug platform provides a new direction to develop the next-generation of drug delivery system for lung cancer.

Enhanced Immunogenic Cell Death and Antigen Presentation via Engineered Bifidobacterium bifidum to Boost Chemo-immunotherapy.

The immunogenic cell death (ICD) of tumor cells has aroused great interest in the field of immunotherapy, mainly due to the production of plentiful tumor-associated antigens (TAAs) and damage-associated molecule patterns. However, doxorubicin (DOX)-induced tumor-specific T-cell-mediated immune response is usually very weak because of antigen presentation deficiency and the immunosuppressive tumor microenvironment (ITME). Herein, the probiotic Bifidobacterium bifidum (Bi) was covalently modified with DOX-loaded CaP/SiO2 nanoparticles (DNPs@Bi) for tumor therapy. On one hand, the pH-responsive release of DOX could induce chemotherapy and ICD in the ITME. On the other hand, tumor-targeting Bi is able to significantly enhance the presentation of TAAs from B16F10 cells to DCs via Cx43-dependent gap junctions. Due to the combination of enhanced ICD and TAAs presentation, the maturation of DCs and the infiltration of cytotoxic T lymphocytes in the ITME were stimulated. As a result, in vivo antitumor experiments demonstrated that DNPs@Bi prolonged the survival rate and significantly inhibited the tumor progression and metastasis. This strategy of bacterial-driven hypoxia-targeting delivery systems offers a promising approach to tumor chemo-immunotherapy.

Functional Titanium Substrates Synergetic Photothermal Therapy for Enhanced Antibacterial and Osteogenic Performance via Immunity Regulation.

Implant-associated infections (IAIs) significantly impair the integration between titanium (Ti) implants and bone tissues. Bacteria colonized on the surface of the implant can induce innate immune suppression of the host to resist clearance. Herein, an interfacial functionalization strategy is employed to introduce FeIII TA nanoparticles (NPs) and acetyl Bletilla striata polysaccharide (acBSP) on the Ti substrate to obtain the Ti-TF-acBSP system. Under near-infrared (NIR) irradiation, the hyperthermal effect induced by FeIII TA NPs directly killed bacteria. Meanwhile, macrophages are induced by acBSP to polarize into pro-inflammatory M1 phenotype, which enhanced the phagocytosis ability of macrophages and activated host innate immunity. Moreover, the asBSP instructed macrophages to secrete pro-osteogenic cytokine, which promoted osteogenic differentiation of MSCs. The results of the animal experiment in vivo confirmed that the Ti-TF-acBSP implant effectively eliminated bacterial infection under NIR irradiation, enhanced the expression of pro-inflammatory cytokine, and induced the production of bone-forming related factors. In a word, the functionalized Ti implant not only have a direct bactericidal effect but also regulate macrophage polarization as well as macrophage-mediated bactericidal and osteogenic effect. The strategy of combining photothermal therapy with immunoregulation will present a potential candidate for the development of novel antibacterial orthopedic devices.

Double-drug loading upconversion nanoparticles for monitoring and therapy of a MYC/BCL6-positive double-hit diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is a systemic hematological malignancy. Herein, through whole exome sequencing (WES), we found that DLBCL genome changes and expression characteristics are associated with various immune cells. Lenalidomide (Len) is a leading candidate for the immunomodulatory treatment of multiple myeloma in the clinic. Inspired by lenalidomide as an immunomodulatory drug for the treatment of multiple myeloma, we constructed a multifunctional nanoplatform with therapeutic and imaging properties for DLBCL by co-loading lenalidomide and dexamethasone (Dex) with upconversion nanoparticles using a GSH-sensitive linker (named as UCNPs-Len-Dex). In vitro cell experiments proved that the UCNPs-Len-Dex had good biocompatibility and obvious antitumor efficacy. UCNPs-Len-Dex also exhibited excellent anti-tumor efficacy and imaging properties in vivo. RNA sequencing showed that UCNPs-Len-Dex targeted and activated the E3 ligase of CRBN, resulting in IKZF1/3 degradation, which inhibited MYC/BCL6-positive DLBCL and maintained the stability of the immune microenvironment. Therefore, this study provided a new monitoring and therapeutic synergetic strategy for DLBCL.

Doxorubicin-loaded polypyrrole nanovesicles for suppressing tumor metastasis through combining photothermotherapy and lymphatic system-targeted chemotherapy.

The lymphatic system provides a main route for the dissemination of most malignancies, which was related to high mortality in cancer patients. Traditional intravenous chemotherapy is of limited effectiveness on lymphatic metastasis due to the difficulty in accessing the lymphatic system. Herein, a novel lymphatic-targeting nanoplatform is prepared by loading doxorubicin (DOX) into sub-50 nm polypyrrole nanovesicles (PPy NVs). The PPy NVs possessed hollow spherical morphologies and a negative surface charge, leading to high drug loading capacity. These vesicles can also convert near-infrared (NIR) light into heat and thus can be used for tumor thermal ablation. DOX loaded PPy NVs (PPy@DOX NVs) along with NIR illumination are highly effective against 4T1 breast cancer cells in vitro. More importantly, following subcutaneous (SC) injection, a direct lymphatic migration of PPy@DOX NVs is confirmed through fluorescence observation of the isolated draining nodes. The acidic conditions in metastatic nodes might subsequently trigger the release of the encapsulated DOX NVs based on their pH-sensitive release profile. In a mouse model bearing 4T1 breast cancer, lymphatic metastases, as well as lung metastases, are significantly inhibited by nanocarrier-mediated trans-lymphatic drug delivery in combination with photothermal ablation. In conclusion, this platform holds great potential in impeding tumor growth and metastasis.

Multi-responsive nanotheranostics with enhanced tumor penetration and oxygen self-producing capacities for multimodal synergistic cancer therapy.

Incorporation of multiple functions into one nanoplatform can improve cancer diagnostic efficacy and enhance anti-cancer outcomes. Here, we constructed doxorubicin (DOX)-loaded silk fibroin-based nanoparticles (NPs) with surface functionalization by photosensitizer (N770). The obtained nanotheranostics (N770-DOX@NPs) had desirable particle size (157 nm) and negative surface charge (-25 mV). These NPs presented excellent oxygen-generating capacity and responded to a quadruple of stimuli (acidic solution, reactive oxygen species, glutathione, and hyperthermia). Surface functionalization of DOX@NPs with N770 could endow them with active internalization by cancerous cell lines, but not by normal cells. Furthermore, the intracellular NPs were found to be preferentially retained in mitochondria, which were also efficient for near-infrared (NIR) fluorescence imaging, photothermal imaging, and photoacoustic imaging. Meanwhile, DOX could spontaneously accumulate in the nucleus. Importantly, a mouse test group treated with N770-DOX@NPs plus NIR irradiation achieved the best tumor retardation effect among all treatment groups based on tumor-bearing mouse models and a patient-derived xenograft model, demonstrating the unprecedented therapeutic effects of trimodal imaging-guided mitochondrial phototherapy (photothermal therapy and photodynamic therapy) and chemotherapy. Therefore, the present study brings new insight into the exploitation of an easy-to-use, versatile, and robust nanoplatform for programmable targeting, imaging, and applying synergistic therapy to tumors.

Oral nanotherapeutics based on Antheraea pernyi silk fibroin for synergistic treatment of ulcerative colitis.

Ulcerative colitis (UC) with its rapidly increasing incidence has become an emerging challenge for public health. Therapeutic agents are required to be specifically delivered to colon epithelial cells and macrophages with controlled release in the cytoplasm for wound healing, inflammation alleviation, and microbiota rebalance. As a promising biomaterial for accomplishing this, Antheraea pernyi silk fibroin (ApSF) was selected and engineered to form nanoparticles (NPs) loaded with the anti-inflammatory drug, resveratrol (Res). The intrinsic features of these fabricated Res-ApNPs included targeting of colonic epithelial cells and macrophages, lysosomal escape capacity, and responsiveness to pH, reactive oxygen species (ROS), and glutathione, which were pertinent to their functional units such as arginine-glycine-aspartate tripeptides, α-helixes, ß-sheets, and disulfide bonds, enabling on-demand release of Res molecules in the cytoplasm of target cells. The Res-ApNP treatment restored damaged colonic epithelial barriers, polarized macrophages to type M2, alleviated inflammatory reactions, and reduced the level of intracellular ROS. Oral treatment with chitosan-alginate hydrogels embedded with Res-ApNPs substantially relieved UC symptoms, as evidenced by decreased colonic inflammation, increased synthesis of tight-junction proteins, and rebalanced intestinal microbiota. Our findings suggest that these high-performance ApSF-based NPs can be developed as effective drug carriers for oral UC treatment.

Fabrication of a pH-responsive core-shell nanosystem with a low-temperature photothermal therapy effect for treating bacterial biofilm infection.

Recently, photothermal therapy (PTT) has been recognized as a viable alternative strategy against bacterial biofilm infection. However, the hyperthermia required for PTT to ablate a biofilm usually induces damage in normal tissues/organs nearby. Herein, we developed zeolite-based imidazole framework (ZIF-8)-coated mesoporous polydopamine (MPDA) core-shell nanoparticles and then loaded Pifithrin-µ (PES), a natural inhibitor of heat-shock protein (HSP) that plays an essential role in bacteria resisting heating-induced damage. The ZIF-8 shell of the MPDA@ZIF-8/PES nanoplatform enabled a rapid degradation in response to the acidic environment in bacterial biofilm infection, which triggered the controlled release of PES and Zn ions. As a result, HSP was remarkably suppressed for enhancing PTT efficacy upon mild near-infrared light irradiation. In addition, the release of Zn2+ also had an antibacterial/antibiofilm effect. Thus, the fabricated nanosystem was able to induce the effective elimination of the bacterial biofilm, realizing low-temperature PTT (∼45 °C) with excellent antibacterial efficacy. This work presented here not only provides a facile approach to fabricate the MPDA@ZIF-8/PES nanosystem with the responsiveness of the bacterial infection environment, but also proposes a promising low-temperature PTT strategy to treat bacterial biofilm-infection effectively.

Quadruple-responsive nanoparticle-mediated targeted combination chemotherapy for metastatic breast cancer.

The synergism of combination chemotherapy can only be achieved under specific drug ratios. Herein, hyaluronic acid (HA)-functionalized regenerated silk fibroin-based nanoparticles (NPs) were used to concurrently deliver curcumin (CUR) and 5-fluorouracil (5-FU) at various weight ratios (3.3 : 1, 1.6 : 1, 1.1 : 1, 1 : 1, and 1 : 1.2) to breast tumor cells. The generated HA-CUR/5-FU-NPs were found to have desirable particle sizes (around 200 nm), narrow size distributions, and negative zeta potentials (about -26.0 mV). Interestingly, these NPs showed accelerated drug release rates when they were exposed to buffers that mimicked the multi-hallmarks in the tumor microenvironment (pH/hydrogen peroxide/glutathione/hyaluronidase). The surface functionalization of NPs with HA endowed them with in vitro and in vivo breast tumor-targeting properties. Furthermore, we found that the co-loading of CUR and 5-FU in HA-functionalized NPs exhibited obvious synergistic anti-cancer, pro-apoptotic, and anti-migration effects, and the strongest synergism was found at the CUR/5-FU weight ratio of 1 : 1.2. Most importantly, mice experiments revealed that HA-CUR/5-FU-NPs (1 : 1.2) showed a superior anti-cancer activity against metastatic breast cancer compared to the single drug-loaded NPs and non-functionalized CUR/5-FU-NPs (1 : 1.2). Collectively, these results demonstrate that HA-CUR/5-FU-NPs (1 : 1.2) can be exploited as a robust nanococktail for the treatment of breast cancer and its lung metastasis.

Oral nanotherapeutics with enhanced mucus penetration and ROS-responsive drug release capacities for delivery of curcumin to colitis tissues.

The therapeutic efficacies of oral nanotherapeutics for ulcerative colitis (UC) are seriously hindered by the lack of mucus-penetrating capacity and uncontrolled drug release. To overcome these limitations, the surface of poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs) was functionalized with pluronic F127 (PF127), and catalase (CAT)/curcumin (CUR) was co-encapsulated into these NPs. The obtained P-CUR/CAT-NPs had a hydrodynamic particle size of approximately 274.1 nm, narrow size distribution, negative zeta potential (-14.0 mV), and smooth surface morphology. Moreover, the introduction of PF127 to the surface of NPs not only facilitated their mucus penetration, but also improved their cellular uptake efficiency by the target cells (macrophages). We further found that the encapsulation of CAT could remarkably increase the release rate of CUR from NPs in the presence of an H2O2-rich environment. Additionally, P-CUR/CAT-NPs showed the strongest capacity to suppress the secretion of the main pro-inflammatory cytokines, in comparison with their counterparts (CUR-NPs and P-CUR-NPs). Importantly, oral administration of P-CAT/CUR-NPs showed the best therapeutic outcomes than the other NPs. Collectively, these results clearly demonstrate that these mucus-penetrating NPs loaded with CAT and CUR can be exploited as an efficient nanotherapeutic for UC therapy.

Inhibition of growth and lung metastasis of breast cancer by tumor-homing triple-bioresponsive nanotherapeutics.

Lung metastasis of breast cancer is a leading cause of cancer-related death in women. Herein, we attempted to simultaneously inhibit the growth and lung metastasis of breast cancer by delivering quercetin (QU) using LyP-1-functionalized regenerated silk fibroin-based nanoparticles (NPs). The generated LyP-1-QU-NPs had a desirable diameter (203.2 nm) and a negatively charged surface (-12.7 mV). Interestingly, these NPs exhibited intrinsic responsibilities when triggered by various stimulating factors in the tumor microenvironment (acidic pH, reactive oxygen species, and glutathione). In vitro experiments revealed that the introduction of LyP-1 to the NP surface could significantly increase their cellular uptake efficiencies by 4 T1 cells, and facilitate their accumulation in mitochondria. Moreover, LyP-1-QU-NPs showed the strongest mitochondrial damage effect among all the treatment groups. We also found that LyP-1-QU-NPs not only exhibited excellent pro-apoptotic activities but also presented strong inhibitory effects on cell mobility (migration and invasion) through anti-glycolysis and pro-autophagy. Mice experiments confirmed that LyP-1-QU-NPs could efficiently inhibit the in situ growth of breast tumors and further restrict their lung metastasis. Collectively, our results demonstrate that LyP-1-QU-NPs, which integrates the functions of tumor cell targeting, mitochondria targeting, bioresponsive drug release, pro-apoptosis, and anti-mobility, can be developed as a promising nanotherapeutic for the effective treatment of breast cancer and its lung metastasis.

Multi-responsive nanococktails with programmable targeting capacity for imaging-guided mitochondrial phototherapy combined with chemotherapy.

The integration of multimodal functions into one nanoplatform holds great promise for enhancing anticancer drug action and mitigating adverse effects. Herein, we prepared hyaluronic acid-functionalized regenerated silk fibroin-based nanoparticles (NPs) loading with photosensitizer (NIR770) and doxorubicin (DOX). The resultant HNDNPs had a desirable diameter of 161.0 nm and a negative zeta-potential of -30.5 mV. Interestingly, they showed excellent responses when triggered with various stimuli (acidity, reactive oxygen species, glutathione, hyaluronidase, or hyperthermia). Cell experiments revealed that HNDNPs could be specifically internalized by A549 cells, and efficiently released the payloads into the cytoplasm. Moreover, NIR770 was preferentially retained in mitochondria due to its lipophilic and cationic properties, which exhibited highly efficient photothermal therapy and photodynamic therapy upon near infrared (NIR) irradiation. Meanwhile, DOX molecules were mainly accumulated in the nucleus. Intravenous injection of HNDNPs into mice followed by NIR irradiation provided excellent multimodal imaging (NIR, photothermal, and photoacoustic imaging), almost eliminated the entire tumor, and greatly prolonged mice survival time with no side effects. Our study demonstrates that this HNDNP, which integrates the functions of tumor targeting, on-demand drug release, multimodal imaging, mitochondrial phototherapy, and chemotherapy, can be exploited as a promising nanococktail for imaging-guided synergistic treatment of cancer.

Injectable, Thixotropic, and Multiresponsive Silk Fibroin Hydrogel for Localized and Synergistic Tumor Therapy.

Combinational cancer therapy offers a promising strategy to overcome the limitations of single-drug treatment, including limited therapeutic efficacy, serious side effects, and low survival rate. Injectable silk fibroin (SF) hydrogel has emerged as an effective platform for localized treatment. Herein, hydrophilic SF (HSF) was extracted from regenerated SF and self-assembled into hydrogel within 2-6 h. The obtained HSF hydrogel showed obvious viscoelasticity, thixotropic behavior, and self-healing performance. Interestingly, this hydrogel also exhibited excellent stimuli-responsive drug release profiles when triggered by multiple factors (acidity, reactive oxygen species, glutathione, hyperthermia, and near-infrared (NIR)), suggesting that it could achieve spatially and temporally on-demand drug release in response to tumor microenvironment and extra-tumor NIR irradiation. Importantly, intratumoral injection of doxorubicin (DOX)/Cy7-loaded HSF-based hydrogel (DOX/Cy7-hydrogel) plus NIR irradiation exerted the best antitumor effect among all the treatment groups, revealing the strong synergistic effects of chemo/photothermal/photodynamic therapy. It is worth noting that this DOX/Cy7-hydrogel could almost eliminate the entire tumor masses, significantly prolonging the survival time of tumor-bearing mice over 60 days without detectable adverse effects. Collectively, our findings suggest that this injectable DOX/Cy7-hydrogel with thixotropic and multistimuli responsive properties could be developed as a promising platform for localized and synergistic treatment of cancer.

Silk fibroin-based nanotherapeutics: application in the treatment of colonic diseases.

The incidence of colonic diseases (e.g., inflammatory bowel diseases and colon cancer) is rapidly rising. Nanotherapeutic has been considered as a promising strategy in the treatment of colonic diseases. Silk fibroin (SF) has been widely used as a drug-carrier matrix. Interestingly, SF-based nanoparticles (SFNPs) have intrinsic anti-inflammatory activity, wound healing capacity and lysosomal environment-responsive drug-release property. With further investigations, the sequences of SF molecules could be precisely modified through chemical reactions or transgenic techniques to greatly improve the properties of SFNPs. Here, we review recent advances in the application of SFNPs toward the treatment of colonic diseases. We also discuss future developments that might improve the anti-inflammatory and anti-colon cancer activities of SF-based nanotherapeutics.

Multi-bioresponsive silk fibroin-based nanoparticles with on-demand cytoplasmic drug release capacity for CD44-targeted alleviation of ulcerative colitis.

The requirement for the favorable therapeutics against ulcerative colitis (UC) is that anti-inflammatory drugs can be specifically internalized by macrophages and subsequently be on-demand released to suppress inflammation. Herein, we developed a type of multi-bioresponsive anti-inflammatory drug (curcumin, CUR)-loaded nanoparticles (NPs) that were derived from natural silk fibroin and followed by surface functionalization with chondroitin sulfate (CS). The generated CS-CUR-NPs had a desired average particle size (175.4 nm), a uniform size distribution and negative surface charge (-35.5 mV). Strikingly, these NPs exhibited excellent bioresponsibility when triggered with the intrinsic stimuli (acidity, glutathione and reactive oxygen species) within activated macrophages, indicating that they could conceivably confer the on-demand intracellular drug release. Furthermore, we found that CS functionalization yielded notably targeted drug delivery to macrophages, and thereby enhanced the anti-inflammatory activities of NPs. Most importantly, animal experiments revealed that these nanotherapeutics could remarkably alleviate the symptoms of UC, maintain the homeostasis of intestinal microbiota and improve the survival rate of mice with UC through the route of oral administration or intravenous injection. Our results suggest that these facilely fabricated CS-CUR-NPs, which exhibit excellent biocompatibility, multi-bioresponsive drug release and macrophage-targeted capacity, could be exploited as a promising therapeutic platform for clinical UC treatment.

Modulation of drug release by decoration with Pluronic F127 to improve anti-colon cancer activity of electrospun fibrous meshes.

Applications of fibrous meshes for localized chemotherapy have been limited by the lack of optimal carriers that are capable of releasing sufficient drug locally. To overcome this obstacle, we introduced Pluronic F127 (PF127) to the camptothecin (CPT)-loaded poly(lactic acid/glycolic acid) (PLGA) electrospun fibrous meshes, abbreviated as PPC, for modulation of drug release. These PPC meshes had smooth surface and high drug loading (5.6-6.8%). Addition of PF127 obviously improved the hydrophilicity of the meshes. Interestingly, the CPT release rate of PPC meshes was significantly higher than that of CPT-loaded PLGA (PLGA-CPT) meshes. Most importantly, incorporation of PF127 in the meshes led to significant reduction in the CT-26 viability compared to PLGA-CPT mesh. The improved anticancer effects of PPC meshes were mainly due to the induction of apoptosis in CT-26 cells. These findings suggest that PPC mesh could be a promising implantable system that may enhance the therapeutic efficacy and prevent tumor recurrence after surgical resection.

Porous Polymeric Microparticles as an Oral Drug Platform for Effective Ulcerative Colitis Treatment.

Porous microparticles (MPs) have been regarded as a promising vehicle for drug delivery. Herein, porous MPs and their counterparts (nonporous MPs) were produced by a conventional emulsion-solvent evaporation method in the presence and absence of ammonium bicarbonate, and curcumin was encapsulated into these MPs during the preparation process. The obtained MPs possessed desirable diameters of around 1.2 µm and negative zeta potentials of approximately -28 mV. It was found that the release rate of curcumin was remarkably increased with the introduction of pores in MPs. Furthermore, orally administered porous MPs achieved statistically significantly better therapeutic outcomes against ulcerative colitis mouse model induced by dextran sulfate sodium, in comparison to nonporous MPs. These findings confirmed that porous MPs could be served as a promising platform for the treatment of ulcerative colitis via oral route.