The effects of stiffness on the specificity and avidity of antibody-coated microcapsules with target cells are strongly shape dependent.

Antibody modification is a common method for endowing drug carriers with the ability to target specific cells. Recent studies suggest that the efficacy of these antibody-modified drug carriers is closely related to their physicochemical properties, such as size, shape, stiffness, charge, and surface chemistry. In this study, we functionalized microcapsules with antibodies to investigate the combined effect of shape and stiffness on their targeting ability. We synthesized hollow microcapsules, both spherical and rod-shaped, with adjustable stiffness using calcium carbonate particles as templates and silk fibroin (SF) as the shell material. These microcapsules were then functionalized with trastuzumab (TTZ) to enhance targeting capabilities. Our analysis revealed that increasing stiffness significantly improved the specificity and avidity of TTZ-coated rod-shaped microcapsules, but not spherical ones, indicating a strong shape-dependent influence of stiffness on these properties. Additionally, we explored the mechanisms of endocytosis using various inhibitors and found that both macropinocytosis and clathrin played critical roles in the cellular uptake of microcapsules. Furthermore, we loaded microcapsules with doxorubicin (DOX) to evaluate their anti-tumor efficacy. The stiffest TTZ-coated, DOX-loaded rod-shaped microcapsules demonstrated the most potent anti-tumor effects on BT-474 cells and the highest uptake in BT-474 3D spheroids. This research contributes to the development of more effective microcapsule-based target delivery systems and the realization of the full potential of microcapsule drug delivery systems.

Platelet membrane-based biochemotactic-targeting nanoplatform combining PDT with EGFR inhibition therapy for the treatment of breast cancer.

Presently, the commonly used anti-tumor drugs lack targeting ability, resulting in a limited therapeutic efficacy and significant side effects. In this view, platelet membranes (PMs) not only exhibit specific binding of its P-selectin protein with CD44, which is highly expressed on breast cancer cells, to promote tumor-active targeting by PM biomimetic nanoplatforms, but also respond to vascular damage, thus inducing biochemotactic targeting to further facilitate the aggregation of these nanoplatforms. Therefore, in this study, a PM was applied to construct a biochemotactic-targeting nanotherapeutic platform based on dendritic large pore mesoporous silica nanoparticles (DLMSNs) co-loaded with chlorin e6 (Ce6) and lapatinib (LAP) to achieve the combination of photodynamic therapy (PDT) and EGFR inhibition therapy for breast cancer. Under laser irradiation, PM@DLMSN/Ce6/Lap could not only effectively kill breast tumor cells by the PDT, but also damage blood vessels. By combining the EGFR inhibition of LAP, PM@DLMSN/Ce6/Lap could better inhibit the migration and movement of tumor cells. In vitro and in vivo results showed that PM@DLMSN/Ce6/Lap could achieve active-targeting drug delivery to breast tumors and further recruit more nanoparticles to accumulate at tumor sites after the PDT-induced damage of blood vessels through biochemotactic targeting, achieving continuous EGFR inhibition to prevent tumor proliferation and metastasis. In conclusion, this study not only provides a new strategy for the clinical treatment of breast cancer, but also provides a design idea for improving the targeted delivery of anti-tumor drugs.

PEI-Based Nanoparticles for Tumor Immunotherapy via In Situ Antigen-Capture Triggered by Photothermal Therapy.

Activating a tumor antigen-specific immune response is key to the success of tumor immunotherapy and the development of personalized antitumor therapy. Nanocarriers can capture, enrich, and protect in situ produced tumor antigens due to immunogenic cell death (ICD), thus enhancing the tumor-specific immune response. Developing multifunctional nanocarriers that combine multiple antigen capturing mechanisms is crucial to the activation of tumor-specific immune responses. In this study, polyethylenimine (PEI) was employed as a main building block to construct a series of multifunctional indocyanine green (ICG)-loaded nanoparticles to capture antigens via multiple mechanisms: electrostatic interactions with PEI, hydrophobic interactions with the thermosensitive segment (POEGMA300), and covalent bonding with the pyridyl disulfide (PDS) groups, respectively. Their capacity of ICD induction, tumor antigen-capture, and antitumor immune responses were evaluated. Both the intrinsic toxicity of PEI and the ICG-mediated photothermal effect were responsible for inducing ICD. The positively charged PEI segment exhibited the best antigen-capturing ability via electrostatic interactions, promoted bone marrow-derived dendritic cell maturation and CD8+ T cell proliferation, and elicited antitumor immune responses in vivo. PDS groups bonded antigens covalently and significantly contributed to the suppression of distant tumor growth. Although the thermosensitive hydrophobic polymer segment did not contribute positively to antigen capture or tumor growth inhibition, NPs containing all of the functional modules prolonged the survival of tumor-bearing mice more than other treatments. This study provides more chemical insights into the design of polymer-based in situ nanovaccines against cancer.

Synergistic wound repair effects of a composite hydrogel for delivering tumor-derived vesicles and S-nitrosoglutathione.

Treating chronic wounds requires transition from proinflammatory M1 to anti-inflammatory M2 dominant macrophages. Based on the role of tumor extracellular vesicles (tEVs) in regulating the phenotypic switching from M1 to M2 macrophages, we propose that tEVs may have a beneficial impact on alleviating the overactive inflammatory microenvironment associated with refractory wounds. On the other hand, as a nitric oxide donor, S-nitrosoglutathione (GSNO) can regulate inflammation, promote angiogenesis, enhance matrix deposition, and facilitate wound healing. In this study, a guar gum-based hydrogel with tEVs and GSNO was designed for the treatment of diabetic refractory wounds. This hybrid hydrogel was formed through the phenyl borate bonds, which can automatically disintegrate in response to the high reactive oxygen species (ROS) level at the site of refractory diabetic wounds, releasing tEVs and GSNO. We conducted a comprehensive evaluation of this hydrogel in vitro, which demonstrated excellent performance. Meanwhile, using a full-thickness excision model in diabetic mice, the wounds exposed to the therapeutic hydrogel healed completely within 21 days. The increased closure rate was associated with macrophage polarization and collagen deposition, accelerated fibroblast proliferation, and increased angiogenesis in the regenerating tissues. Therefore, this multifunctional hybrid hydrogel appears to be promising for clinical applications.

Antioxidative and antibacterial gallium (III)-phenolic coating for enhanced osseointegration of titanium implants via pro-osteogenesis and inhibiting osteoclastogenesis.

Improving the ability of implants to integrate with natural bone tissue at the initial stage of implantation remains a huge challenge because bone-to-implant interfaces are often accompanied by abnormal microenvironments with infection, reactive oxygen species (ROS) and unbalanced bone homeostasis. In this study, a multifunctional coating was fabricated on the basis of gallium (III)-phenolic networks. It is easily obtained by immersing the implants into a mixed solution of tannic acids (TAs) and gallium ions. The thickness of the coating can be precisely controlled by adjusting the number and time of immersion experiments. The resulting coating displays excellent near-infrared photothermal property. As the coating degrades, TAs and gallium ions with low concentration are released from the coating, which is more rapid in acidic and oxidative stress microenvironments. Photothermal performance as well as released TAs and gallium ions give the coating outstanding broad-spectrum antibacterial ability. Furthermore, the coating effectively reduces intracellular ROS of osteoblasts. In vitro and in vivo experiments demonstrate the capability of the coating enhancing implants' osseointegration via pro-osteogenesis and inhibiting osteoclastogenesis. The findings imply that gallium (III)-phenolic coating holds great promise to promote implant osseointegration by rescuing abnormal microenvironments of infection, oxidative stress and unbalanced bone homeostasis.

Platelet Rich Plasma Loaded Multifunctional Hydrogel Accelerates Diabetic Wound Healing via Regulating the Continuously Abnormal Microenvironments.

Continuous oxidative stress and cellular dysfunction caused by hyperglycemia are distinguishing features of diabetic wounds. It has been a great challenge to develop a smart dressing that can accelerate diabetic wound healing through regulating abnormal microenvironments. In this study, a platelet rich plasma (PRP) loaded multifunctional hydrogel with reactive oxygen species (ROS) and glucose dual-responsive property is reported. It can be conveniently prepared with PRP, dopamine (DA) grafted alginate (Alg-DA), and 6-aminobenzo[c][1,2]oxaborol-1(3H)-ol (ABO) conjugated hyaluronic acid (HA-ABO) through ionic crosslinks, hydrogen-bond interactions, and boronate ester bonds. The hydrogel possesses injectability, moldability, tissue adhesion, self-healing, low hemolysis, and hemostasis performances. Its excellent antioxidant property can create a low oxidative stress microenvironment for other biological events. Under an oxidative stress and/or hyperglycemia state, the hydrogel can degrade at an accelerated rate to release a variety of cytokines derived from activated blood platelets. The result is a series of positive changes that are favorable for diabetic wound healing, including fast anti-inflammation, activated macrophage polarization toward M2 phenotype, promoted migration and proliferation of fibroblasts, as well as expedited angiogenesis. This work provides an efficient strategy for chronic diabetic wound management and offers an alternative for developing a new-type PRP-based bioactive wound dressing.

High-Coverage Strategy for Multi-Subcellular Metabolome Analysis Using Dansyl-Labeling-Based LC-MS/MS.

Subcellular compartmentalization ensures orderly and efficient intracellular metabolic activities in eukaryotic life. Investigation of the subcellular metabolome could provide in-depth insight into cellular biological activities. However, the sensitive measurement of multi-subcellular metabolic profiles is still a significant challenge. Herein, we present a comprehensive subcellular fractionation, characterization, and metabolome analysis strategy. First, six subcellular fractions including nuclei, mitochondria, lysosomes, peroxisomes, microsomes, and cytoplasm were generated from a single aliquot of liver homogenate. Then, a dansyl-labeling-assisted liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring 151 amino/phenol- or carboxyl-containing metabolites in the subcellular fractions was established and validated. Last, the strategy was applied to a rat model of carbon tetrachloride (CCl4)-induced acute liver injury (ALI). The metabolic profile of individual organelles was compared with that of the liver. Interestingly, many unique changes were observed specifically in organelles, while the liver failed to capture these changes. This result indicates that metabolic investigation at the tissue level might lead to erroneous results due to the leveling effect. Our study demonstrates a feasible approach for the broad-spectrum-targeted metabolic profiling of multi-subcellular fractions, which can be of great use in driving our further understanding of intracellular metabolic activities in various physical and pathological conditions.

Drug self-framework delivery system-coated gold nanorods for multi-modal imaging and combination therapy for breast cancer.

Herein, we report a multifunctional nanodrug (Au NRs@DSFDSs NPs) by coating a drug self-framework delivery system (DSFDS) on Au NRs with absorption at 1300 nm via simple condensation polymerization, with the purpose of developing an efficient theranostic nanoagent with multi-modal imaging ability, and synergistic chemo-photothermal therapy (CT-PTT) for the monitoring and suppression of tumor growth. Thus, this strategy provides a new idea for the design of a multifunctional platform for the accurate and effective image-guided treatment of tumors.

Endoplasmic reticulum-targeted NIR-II phototherapy combined with inflammatory vascular suppression elicits a synergistic effect against TNBC.

Recurrence and metastasis are the main reasons for failure in the treatment of triple-negative breast cancer (TNBC). Phototherapy, one of the most well-known potent cancer treatment models is highlighted by ablating primitive tumors with immunogenic cell death (ICD) and is associated with endoplasmic reticulum (ER) stress to elicit long-lasting anti-tumor immunity. However, the provoked inflammatory response after phototherapy will stimulate angiogenesis, which provides nutrition for tumor recurrence. Here, an ER-targeted nanoplatform was constructed based on hollow mesoporous Cu2-XS (HMCu2-XS) nanoparticles to suppress recurrence and metastasis of TNBC by combining photo-ablation and microenvironment remodeling. Profiting from the metal ion coordination and large hollow space, HMCu2-XS can be easily modified with p-toluenesulfonamide for ER-targeting and quantitatively loaded celecoxib (CXB) as a vascular inhibitor, thus obtaining ER-HMCu2-XS/CXB. ER-HMCu2-XS showed great photothermal and photodynamic efficiency for ablating 4T1 tumors and inducing ICD under NIR-II laser irradiation. Compared with non-ER-targeted nanosystems, the ER-targeted nanosystem elicited stronger ICDs and recruited more immune cells. Moreover, the thermal-responsively released CXB successfully inhibited angiogenesis after photothermal therapy. The data showed that the ER-HMCu2-XS/CXB mediated the triplicate therapeutic effect of photo-ablation, immune response activation, and vascular suppression effectively, preventing the recurrence and metastasis of TNBC. In conclusion, this work provides a synergistic strategy to enhance therapeutic outcomes in TNBC.

Discovery of toxoflavin, a potent IRE1α inhibitor acting through structure-dependent oxidative inhibition.

Inositol-requiring enzyme 1α (IRE1α) is the most conserved endoplasmic reticulum (ER) stress sensor with two catalytic domains, kinase and RNase, in its cytosolic portion. IRE1α inhibitors have been used to improve existing clinical treatments against various cancers. In this study we identified toxoflavin (TXF) as a new-type potent small molecule IRE1α inhibitor. We used luciferase reporter systems to screen compounds that inhibited the IRE1α-XBP1s signaling pathway. As a result, TXF was found to be the most potent IRE1α RNase inhibitor with an IC50 value of 0.226 µM. Its inhibitory potencies on IRE1α kinase and RNase were confirmed in a series of cellular and in vitro biochemical assays. Kinetic analysis showed that TXF caused time- and reducing reagent-dependent irreversible inhibition on IRE1α, implying that ROS might participate in the inhibition process. ROS scavengers decreased the inhibition of IRE1α by TXF, confirming that ROS mediated the inhibition process. Mass spectrometry analysis revealed that the thiol groups of four conserved cysteine residues (CYS-605, CYS-630, CYS-715 and CYS-951) in IRE1α were oxidized to sulfonic groups by ROS. In molecular docking experiments we affirmed the binding of TXF with IRE1α, and predicted its binding site, suggesting that the structure of TXF itself participates in the inhibition of IRE1α. Interestingly, CYS-951 was just near the docked site. In addition, the RNase IC50 and ROS production in vitro induced by TXF and its derivatives were negative correlated (r = -0.872). In conclusion, this study discovers a new type of IRE1α inhibitor that targets a predicted new alternative site located in the junction between RNase domain and kinase domain, and oxidizes conserved cysteine residues of IRE1α active sites to inhibit IRE1α. TXF could be used as a small molecule tool to study IRE1α's role in ER stress.

Locally delivered modified citrus pectin - a galectin-3 inhibitor shows expected anti-inflammatory and unexpected regeneration-promoting effects on repair of articular cartilage defect.

Treating the concomitant inflammation in the process of injury and repair, and simultaneously promoting cartilage regeneration is very important for the repair of articular cartilage (AC) defects. Nevertheless, this remains a massive challenge. To address this issue, a collagen membrane-based modified citrus pectin (MCP) delivery system (MCP-C) was developed in this study by targeting galectin-3 (Gal-3), an upstream proinflammatory factor. As expected, MCP shows anti-inflammatory effects; it downregulates the expressions of IL-1ß, MMP13, Gal-3, and COL1A2, inhibits the degenerative effects of Gal-3 on chondrocytes in vitro, and protects chondrocytes from degeneration and death in vivo. Unexpectedly, MCP promotes the proliferation of chondrocytes, upregulates the expression of COL2A1 and SOX9 in the chondrocytes in vitro, and enhances the repair of AC defect in rabbit knee, especially MCP500-C with a complete release of the loading amount of approximately 500 µg/cm2 in a day. Mechanistically, MCP upregulates the expressions of multiple endogenous growth factors for chondrogenesis via the transcriptome sequencing of MCP-treated chondrocytes, and downregulates the expressions of various inflammatory factors. These findings demonstrate that locally delivered MCP can simultaneously modulate both regenerative and inflammatory responses, and can enhance the repair of AC defects.

Facile fabrication of a biodegradable multi-hollow iron phosphate nanoplatform for tumor-specific nanocatalytic therapy and chemotherapy.

In this study, a type of biodegradable multi-hollow iron phosphate (FeP) with excellent Fenton reaction ability and doxorubicin (DOX) loading capacity is synthesized in one-pot. This hollow FeP with complex interior not only affords high drug loading efficiency, but also obviates DOX leakage in normal tissues. In order to inhibit the formation of inert Fe(OH)x and endow the nanoplatform with a highly hydrophilic surface, PEG was anchored to it with a dopamine linkage, which formed an Fe chelating complex. DOX-loaded FeP modified with PEG could be disintegrated when responding to the lysosomal acid environment, releasing both ferric and ferrous ions as well as DOX. Therefore, apart from chemotherapy with DOX, the continuously generated iron ions catalyze a fast Fenton reaction with the innate H2O2 in tumor cells and produce abundant highly toxic hydroxyl radicals for nanocatalytic tumor therapy. Taken together, we believe that this nanoplatform will significantly advance the fields of both Fe-based nanomaterials and nanocatalytic tumor therapy.

The effect of blending poly (l-lactic acid) on in vivo performance of 3D-printed poly(l-lactide-co-caprolactone)/PLLA scaffolds.

Blending poly (l-lactic acid, PLLA) with poly (l-lactide-co-caprolactone, PLCL) is an effective strategy for developing new PLCL/PLLA blend based biomaterials. However, the effect of PLLA on in vivo performance of PLCL/PLLA blends is unclear yet. To address this issue, in this study, the effect of PLLA on in vivo biodegradability and biocompatibility of 3D-printed scaffolds of PLCL/PLLA blend was investigated. Three kinds of different 3D-printed PLCL/PLLA scaffolds using different blends with different mass ratios of the polymers, were prepared and implanted subcutaneously. The shrinkage and tissue responses were monitored by ultrasonography after the implantation. 2 months post-operation, the in vivo performances of the scaffolds were investigated histologically. All scaffolds showed good biocompatibility and allowed fast tissues ingrowth, however PLCL50/PLLA50 scaffold with the highest PLLA ratio induced the thickest the fibrous capsule surrounding the scaffolds and highest inflammatory scores. Furthermore, it was found that the fine porous structures of all scaffolds were well maintained, indicating the 3D-printed scaffolds were degraded through a surface erosion but not bulk erosion way. However, different scaffolds showed different shrinkage and degradation ratios, and PLCL50/PLLA50 scaffold resulted in a significant shrinkage, while PLCL90/PLLA10 scaffold showed the better structural stability. Therefore, PLLA at blending different ratio had different effects on the in vivo performance of 3D-printed PLCL/PLLA scaffolds. Particularly, PLCL/PLLA scaffolds blending with low ratio of PLLA, such as PLCL90/PLLA10 scaffold showed better application potential in tissue engineering. Our findings provide a new insight on the rational design, constrcution and application of the 3D-printed PLCL/PLLA scaffolds.

A small-molecule self-assembled nanodrug for combination therapy of photothermal-differentiation-chemotherapy of breast cancer stem cells.

The combination therapy with different treatment modalities has been widely applied in the clinical applications of cancer treatment. However, it stills a considerable challenge to achieve co-delivery of different drugs because of distinct drug encapsulation mechanisms, low drug loading, and high excipient-related toxicity. Cancer stem cells (CSCs) are closely related to tumor metastasis and recurrence due to high chemoresistance. Herein, we report a stimuli-responsive and tumor-targeted small-molecule self-assembled nanodrug for the combination therapy against CSCs and normal cancer cells. The hydrophobic differentiation-inducing agent (all-trans retinoic acid, ATRA) and hydrophilic anticancer drug (irinotecan, IRI) constitute this amphiphilic nanodrug, which could self-assemble into stable nanoparticles and encapsulate the photothermal agent IR825. Upon cellular uptake, this nanodrug display good release profiles in response to acid and esterase microenvironments by ester linkage. The released drugs not only increase chemotherapy sensitivity by the differentiation of CSCs into non-CSCs, but also exhibit superior cytotoxicity in cancer cells. In addition, IR825 within this nanodrug enables in vivo fluorescence/photoacoustic (PA) imaging allowing for tracking drug distribution. Moreover, the DSPE-PEG-RGD-functionalized nanodrug displayed high tumor accumulation and good biocompatibility, enabling efficient inhibition of tumor growth and tumor metastasis in tumor-bearing mice.

Modification in Silver Staining Procedure for Enhanced Protein Staining.

Silver staining is an excellent technique for detecting proteins that are separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Protein silver staining technology has higher sensitivity and is suitable for the detection of low-concentration proteins compared to other staining techniques including the Coomassie brilliant blue detection method. The present study was conducted to enhance the detection ability of the protein staining method. Herein, we modified the recipe of silver staining, a very reproducible method, by adding AMP, PVP, Tween-80, and xylene to enhance the detection ability of protein staining. Furthermore, the particle size and potentiometer were used to detect the particle size and potential difference of the silver ions in the prepared dyeing materials, and then, the morphology, transparency, and size of the dyed silver particles in different dyeing solutions were studied using a transmission electron microscopy (TEM). The obtained results revealed that the use of 0.5% of AMP, PVP, Tween-80, and xylene improved the staining ability of protein silver staining, compared with the original method. Furthermore, 0.5% AMP, 0.5% PVP, 0.5% Tween-80 reagents significantly influenced the morphology, size, potential, and dispersion of silver ions. These results suggested a new idea for further improving the detection ability of protein silver staining.

Three-Dimensional Printing Self-Healing Dynamic/Photocrosslinking Gelatin-Hyaluronic Acid Double-Network Hydrogel for Tissue Engineering.

Three-dimensional (3D) printing technology has great potential for constructing structurally and functionally complex scaffold materials for tissue engineering. Bio-inks are a critical part of 3D printing for this purpose. In this study, based on dynamic hydrazone-crosslinked hyaluronic acid (HA-HYD) and photocrosslinked gelatin methacrylate (GelMA), a double-network (DN) hydrogel with significantly enhanced mechanical strength, self-healing, and shear-thinning properties was developed as a printable hydrogel bio-ink for extrusion-based 3D printing. Owing to shear thinning, the DN hydrogel bio-inks could be extruded to form uniform filaments, which were printed layer by layer to fabricate the scaffolds. The self-healing performance of the filaments and photocrosslinking of GelMA worked together to obtain an integrated and stable printed structure with high mechanical strength. The in vitro cytocompatibility assay showed that the DN hydrogel printed scaffolds supported the survival and proliferation of bone marrow mesenchymal stem cells. GelMA/HA-HYD DN hydrogel bio-inks with printability, good structural integrity, and biocompatibility are promising materials for 3D printing of tissue engineering scaffolds.

Biomimetic Nanocarriers Guide Extracellular ATP Homeostasis to Remodel Energy Metabolism for Activating Innate and Adaptive Immunity System.

Metabolic interventions via targeting intratumoral dysregulated metabolism pathways have shown promise in reinvigorating antitumor immunity. However, approved small molecule immunomodulators often suffer from ineffective response rates and severe off-target toxicity. ATP occupies a crucial role in energy metabolism of components that form the tumor microenvironment (TME) and influences cancer immunosurveillance. Here, a nanocarrier-assisted immunometabolic therapy strategy that targets the ATP-adenosine axis for metabolic reprogramming of TME is reported. An ecto-enzyme (CD39) antagonist POM1 and AMP-activated protein kinase (AMPK) agonist metformin are both encapsulated into cancer cell-derived exosomes and used as nanocarriers for tumor targeting delivery. This method increases the level of pro-inflammatory extracellular ATP (eATP) while preventing the accumulation of immunosuppressive adenosine and alleviating hypoxia. Elevated eATP triggers the activation of P2X7-NLRP3-inflammasome to drive macrophage pyroptosis, potentiates the maturation and antigen capacity of dendritic cells (DCs) to enhance the cytotoxic function of T cells and natural killer (NK) cells. As a result, synergistic antitumor immune responses are initiated to suppress tumor progress, inhibit tumor distant metastases, provide long-term immune memory that offers protection against tumor recurrence and overcome anti-PD1 resistance. Overall, this study provides an innovative strategy to advance eATP-driven antitumor immunity in cancer therapy.

Gene augmented nuclear-targeting sonodynamic therapy via Nrf2 pathway-based redox balance adjustment boosts peptide-based anti-PD-L1 therapy on colorectal cancer.

BACKGROUND: Colorectal cancer is known to be resistant to immune checkpoint blockade (ICB) therapy. Sonodynamic therapy (SDT) has been reported to improve the efficacy of immunotherapy by inducing immunogenic cell death (ICD) of cancer. However, the SDT efficacy is extremely limited by Nrf2-based natural redox balance regulation pathway in cancer cells in response to the increased contents of reactive oxygen species (ROS). Nuclear-targeting strategy has shown unique advantages in tumor therapy by directly destroying the DNA. Thus it can be seen that Nrf2-siRNA augmented nuclear-targeting SDT could boost ICB therapy against colorectal cancer. RESULTS: The nuclear-targeting delivery system TIR@siRNA (TIR was the abbreviation of assembled TAT-IR780) with great gene carrier capacity and smaller diameter (< 60 nm) was designed to achieve the gene augmented nuclear-targeting SDT facilitating the anti-PD-L1 (programmed cell death-ligand-1) therapy against colorectal cancer. In CT26 cells, TIR@siRNA successfully delivered IR780 (the fluorescent dye used as sonosensitizer) into cell nucleus and Nrf2-siRNA into cytoplasm. Under US (utrasound) irradiation, TIR@siRNA notably increased the cytotoxicity and apoptosis-inducing activity of SDT through down-regulating the Nrf2, directly damaging the DNA, activating mitochondrial apoptotic pathway while remarkably inducing ICD of CT26 cells. In CT26 tumor-bearing mice, TIR@siRNA mediated gene enhanced nuclear-targeting SDT greatly inhibited tumor growth, noticeably increased the T cell infiltration and boosted DPPA-1 peptide-based anti-PD-L1 therapy to ablate the primary CT26 tumors and suppress the intestinal metastases. CONCLUSIONS: All results demonstrate that TIR@siRNA under US irradiation can efficiently inhibit the tumor progression toward colorectal CT26 cancer in vitro and in vivo by its mediated gene augmented nuclear-targeting sonodynamic therapy. Through fully relieving the immunosuppressive microenvironment of colorectal cancer by this treatment, this nanoplatform provides a new synergistic strategy for enhancing the anti-PD-L1 therapy to ablate colorectal cancer and inhibit its metastasis.

Blending with Poly(l-lactic acid) Improves the Printability of Poly(l-lactide-co-caprolactone) and Enhances the Potential Application in Cartilage Tissue Engineering.

Poly(l-lactide-co-caprolactone) (PLCL, 50:50) has been used in cartilage tissue engineering because of its high elasticity. However, its mechanical properties, including its rigidity and viscoelasticity, must be improved for compatibility with native cartilage. In this study, a set of PLCL/poly(l-lactic acid) (PLLA) blends was prepared by blending with different mass ratios of PLLA that range from 10 to 50%, using thermoplastic techniques. After testing the properties of these PLCL/PLLA blends, they were used to fabricate scaffolds by the 3D printing technology. The structures and viscoelastic behavior of the PLCL/PLLA scaffolds were determined, and then, the potential application of the scaffolds in cartilage tissue engineering was evaluated by chondrocytes culture. All blends demonstrate good thermal stability for the 3D printing technology. All blends show good toughness, while the rigidity of PLCL is increased through PLLA blending, and Young's modulus of blends with 10-20% PLLA is similar to that of native cartilage. Furthermore, blending with PLLA improves the processability of PLCL for 3D printing, and the compression modulus and viscoelasticity of 3D-printed PLCL/PLLA scaffolds are different from that of PLCL. Additionally, the stress relaxation time (t 1/2) of the PLCL/PLLA scaffolds, which is important for chondrogenesis, is dramatically shortened compared with the pure PLCL scaffold at the same 3D-printing filling rate. Consistently, the PLCL90PLLA10 scaffold at a 70% filling rate with much shorter t 1/2 is more conducive to the proliferation and chondrogenesis of in vitro seeded chondrocytes accompanied by upregulated expression of SOX9 than the PLCL scaffold. Taken together, these results demonstrate that blending with PLLA improves the printability of PLCL and enhances its potential application, particularly PLCL/PLLA scaffolds with a low ratio of PLLA, in cartilage tissue engineering.