Polyphenol-driven facile assembly of a nanosized acid fibroblast growth factor-containing coacervate accelerates the healing of diabetic wounds.

Diabetic wounds are challenging to heal due to complex pathogenic abnormalities. Routine treatment with acid fibroblast growth factor (aFGF) is widely used for diabetic wounds but hardly offers a satisfying outcome due to its instability. Despite the emergence of various nanoparticle-based protein delivery approaches, it remains challenging to engineer a versatile delivery system capable of enhancing protein stability without the need for complex preparation. Herein, a polyphenol-driven facile assembly of nanosized coacervates (AE-NPs) composed of aFGF and Epigallocatechin-3-gallate (EGCG) was constructed and applied in the healing of diabetic wounds. First, the binding patterns of EGCG and aFGF were predicted by molecular docking analysis. Then, the characterizations demonstrated that AE-NPs displayed higher stability in hostile conditions than free aFGF by enhancing the binding activity of aFGF to cell surface receptors. Meanwhile, the AE-NPs also had a powerful ability to scavenge reactive oxygen species (ROS) and promote angiogenesis, which significantly accelerated full-thickness excisional wound healing in diabetic mice. Besides, the AE-NPs suppressed the early scar formation by improving collagen remodeling and the mechanism was associated with the TGF-ß/Smad signaling pathway. Conclusively, AE-NPs might be a potential and facile strategy for stabilizing protein drugs and achieving the scar-free healing of diabetic wounds. STATEMENT OF SIGNIFICANCE: Diabetic chronic wound is among the serious complications of diabetes that eventually cause the amputation of limbs. Herein, a polyphenol-driven facile assembly of nanosized coacervates (AE-NPs) composed of aFGF and EGCG was constructed. The EGCG not only acted as a carrier but also possessed a therapeutic effect of ROS scavenging. The AE-NPs enhanced the binding activity of aFGF to cell surface receptors on the cell surface, which improved the stability of aFGF in hostile conditions. Moreover, AE-NPs significantly accelerated wound healing and improved collagen remodeling by regulating the TGF-ß/Smad signaling pathway. Our results bring new insights into the field of polyphenol-containing nanoparticles, showing their potential as drug delivery systems of macromolecules to treat diabetic wounds.

Self-Cross-Linked Hydrogel of Cysteamine-Grafted γ-Polyglutamic Acid Stabilized Tripeptide KPV for Alleviating TNBS-Induced Ulcerative Colitis in Rats.

KPV (Lys-Pro-Val), which is a tripeptide derived from α-MSH (α-melanocyte-stimulating hormone), has an anti-inflammatory effect on colitis. However, KPV solution is very unstable when rectally administered, compromising its therapeutic efficacy. Herein, cysteamine-grafted γ-polyglutamic acid (SH-PGA) was synthesized by conjugating cysteamine with the carboxyl groups of γ-PGA. The synthesized SH-PGA has the thiol grafting amount of 4.5 ± 0.3 mmol/g. Without the use of the cross-linker, the SH-PGA hydrogel with 4% of the polymer was formed by self-cross-linking of thiol groups. Moreover, the formation of the SH-PGA hydrogel was not affected by KPV. The KPV/SH-PGA hydrogel presented higher elastic modulus (G') than the corresponding viscous modulus (G″) at 0.01-10 Hz, exhibiting good mechanical stability. The KPV/SH-PGA hydrogel presented a shear-thinning behavior, which was helpful for rectal administration. Only 30% of KPV was released from the KPV/SH-PGA hydrogel within 20 min, followed by a sustained-release behavior. Importantly, the stability of KPV in the SH-PGA hydrogel was obviously enhanced, which was presented by detecting its anti-inflammatory activity and promoting cell migration potential after 2 h of exposure to 37 °C. The enhanced therapeutic effect of the KPV/SH-PGA hydrogel on colitis was confirmed on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced ulcerative colitis rats. The colitis symptoms including body weight loss and the disease activity index score were obviously attenuated by rectally administering the KPV/SH-PGA hydrogel. Besides, the KPV/SH-PGA hydrogel treatment prevented the colon shortening of TNBS-infused rats and decreased the colonic myeloperoxidase level. The morphology of the colon including the epithelial barrier, crypt, and intact goblet cells was recovered after KPV/SH-PGA hydrogel treatment. Besides, the KPV/SH-PGA hydrogel decreased the expression of proinflammatory cytokines such as tumor necrosis factor α and interleukin 6. Collectively, the KPV/SH-PGA hydrogel may provide a promising strategy for the treatment of ulcerative colitis.

Ganoderma Lucidum Polysaccharides Enhance the Abscopal Effect of Photothermal Therapy in Hepatoma-Bearing Mice Through Immunomodulatory, Anti-Proliferative, Pro-Apoptotic and Anti-Angiogenic.

Hepatocellular carcinoma is a malignant tumor with high morbidity and mortality, a highly effective treatment with low side effects and tolerance is needed. Photothermal immunotherapy is a promising treatment combining photothermal therapy (PTT) and immunotherapy. PTT induces the release of tumor-associated antigens by ablating tumor and Ganoderma lucidum polysaccharides (GLP) enhance the antitumor immunity. Results showed that Indocyanine Green (ICG) was successfully encapsulated into SF-Gel. ICG could convert light to heat and SF-Gel accelerates the photothermal effect in vitro and in vivo. PTT based on ICG/ICG-SF-Gel inhibited the growth of primary and distal tumors, GLP enhanced the inhibitory efficacy. ICG/ICG-SF-Gel-based PTT and GLP immunotherapy improved the survival time. ICG/ICG-SF-Gel-based PTT induces tumor necrosis and GLP enhanced the photothermal efficacy. ICG/ICG-SF-Gel-based PTT inhibited cell proliferation and angiogenesis, induced cell apoptosis, enhanced cellular immunity, and GLP enhanced these effects. In conclusion, GLP could enhance the abscopal effect of PTT in Hepatoma-bearing mice.

Magnetic PLGA microspheres loaded with SPIONs promoted the reconstruction of bone defects through regulating the bone mesenchymal stem cells under an external magnetic field.

Superparamagnetic iron oxide nanoparticles (SPIONs) have been presented to regulate the migration and osteogenic differentiation of bone mesenchymal stem cells (BMSCs) under magnetic field (MF). However, the toxicity and short residence for the massively exposed SPIONs at bone defects compromises their practical application. Herein, SPIONs were encapsulated into PLGA microspheres to overcome these shortcomings. Three types of PLGA microspheres (PFe-I, PFe-II and PFe-III) were prepared by adjusting the feeding amount of SPIONs, in which the practical SPIONs loading amounts was 1.83%, 1.38% and 1.16%, respectively. The average diameter of the fabricated microspheres ranged from 160 µm to 200 µm, having the porous and rough surfaces displayed by SEM. Moreover, they displayed the magnetic property with a saturation magnetization of 0.16 emu/g. In vitro cell studies showed that most of BMSCs were adhered on the surface of PFe-II microspheres after 2 days of co-culture. Moreover, the osteoblasts differentiation of BMSCs was significantly promoted by PFe-II microspheres after 2 weeks of co-culture, as shown by detecting osteogenesis-related proteins expressions of ALP, COLI, OPN and OCN. Afterward, PFe-II microspheres were surgically implanted into the defect zone of rat femoral bone, followed by exposure to an external MF, to evaluate their bone repairing effect in vivo. At 6th week after treatment with PFe-II + MF, the bone mineral density (BMD, 263.97 ± 25.99 mg/cm3), trabecular thickness (TB.TH, 0.58 ± 0.08 mm), and bone tissue volume/total tissue volume (BV/TV, 78.28 ± 5.01%) at the defect zone were markedly higher than that of the PFe-II microspheres alone (BMD, 194.34 ± 26.71 mg/cm3; TB.TH, 0.41 ± 0.07 mm; BV/TV, 50.49 ± 6.41%). Moreover, the higher expressions of ALP, COLI, OPN and OCN in PFe-II + MF group were displayed in the repairing bone. Collectively, magnetic PLGA microspheres together with MF may be a promising strategy for repairing bone defects.

Polylysine-bilirubin conjugates maintain functional islets and promote M2 macrophage polarization.

Macrophage polarization is one of the main factors contributing to the proinflammatory milieu of transplanted islets. It causes significant islet loss. Bilirubin exhibits protective effects during the islet transplantation process, but the mode of delivering drugs along with the islet graft has not yet been developed. In addition, it remains unclear whether bilirubin or its derivatives can modulate macrophage polarization during islet transplantation. Therefore, this study aimed to develop an ε-polylysine-bilirubin conjugate (PLL-BR) to encapsulate the islets for protection and to explore its macrophage modulation activities. In in vitro studies, the PLL-BR was shown to tightly adhere to the islet surface. It also exhibited enhanced cytoprotective effects against oxidative and inflammatory conditions by promoting M2-type macrophage polarization. In in vivo studies, the PLL-BR-protected islets successfully prolonged the euglycemia period in diabetic mice and accelerated the blood glucose clearance rate by maintaining the insulin secretion function. Compared to the untreated islets, the PLL-BR-encapsulated islets induced anti-inflammatory responses that were characterized by elevated levels of M2 macrophage markers and local vascularization. In conclusion, PLL-BR can be used as a tool for reprograming macrophage polarization while providing a more efficient immune protection for transplanted islets. STATEMENT OF SIGNIFICANCE: Macrophage polarization is one main factor that caused significant loss of transplanted islets. Bilirubin possesses protective effects toward pancreatic islet, but how to deliver the drug along with the islet graft has not yet been harnessed. More importantly, whether bilirubin or its derivatives could modulate macrophage polarization during the host rejections has also not been answered. In this study, we developed an ε-polylysine-bilirubin conjugate (PLL-BR) to encapsulate the islets and explore its role in macrophage modulation activities. PLL-BR could attach to the surface of islets and exerted high oxidation resistance and anti-inflammatory effect. For the first time, we demonstrate that bilirubin and its derivatives effectively promoted the M2-type macrophage polarization, and optimize the immune microenvironment for islets survival and function.

Glucose-responsive hydrogel enhances the preventive effect of insulin and liraglutide on diabetic nephropathy of rats.

Diabetic nephropathy (DN) is one of the most serious complications of diabetes mellitus. The combination of insulin (Ins) with liraglutide (Lir) has a greater potential for preventing DN than monotherapy. However, the renal protective effect of the combined Ins/Lir therapy is largely compromised due to their short half-lives after subcutaneous injection. Herein, a glucose-responsive hydrogel was designed in situ forming the dynamic boronic esters bonds between phenylboronic acid-grafted γ-Polyglutamic acid (PBA-PGA) and konjac glucomannan (KGM). It was hypothesized that the KGM/PBA-PGA hydrogel as the delivery vehicle of Ins/Lir would enhance the combinational effect of the latter on preventing the DN progress. Scan electronic microscopy and rheological studies showed that KGM/PBA-PGA hydrogel displayed good glucose-responsive property. Besides, the glucose-sensitive release profile of either Ins or Lir from KGM/PBA-PGA hydrogel was uniformly displayed at hyperglycemic level. Furthermore, the preventive efficacy of KGM/PBA-PGA hydrogel incorporating insulin and liraglutide (Ins/Lir-H) on DN progress was evaluated on streptozotocin-induced rats with diabetic mellitus (DM). At 6 weeks after subcutaneous injection of Ins/Lir-H, not only the morphology of kidneys was obviously recovered as shown by ultrasonography, but also the renal hemodynamics was significantly improved. Meanwhile, the 24-h urinary protein and albumin/creatinine ratio were well modulated. Inflammation and fibrosis were also largely inhibited. Besides, the glomerular NPHS-2 was obviously elevated after treatment with Ins/Lir-H. The therapeutic mechanism of Ins/Lir-H was highly associated with the alleviation of oxidative stress and activation of autophagy. Conclusively, the better preventive effect of the combined Ins/Lir via KGM/PBA-PGA hydrogel on DN progress was demonstrated as compared with their mixed solution, suggesting KGM/PBA-PGA hydrogel might be a potential vehicle of Ins/Lir to combat the progression of DN.

HA/MgO nanocrystal-based hybrid hydrogel with high mechanical strength and osteoinductive potential for bone reconstruction in diabetic rats.

Bone repair and regeneration processes are markedly impaired in diabetes mellitus (DM). Intervening approaches similar to those developed for normal healing conditions have been adopted to combat DM-associated bone regeneration. However, limited outcomes were achieved for these approaches. Hence, together with osteoconductive hydroxyapatite (HA) nanocrystals, osteoinductive magnesium oxide (MgO) nanocrystals were uniformly mounted into the network matrix of an organic hydrogel composed of cysteine-modified γ-polyglutamic acid (PGA-Cys) to construct a hybrid and rough hydrogel scaffold. It was hypothesized that the HA/MgO nanocrystal hybrid hydrogel (HA/MgO-H) scaffold can significantly promote bone repair in DM rats via the controlled release of Mg2+. The HA/MgO-H scaffold exhibited a sponge-like morphology with porous 3D networks inside it and displayed higher mechanical strength than a PGA-Cys scaffold. Meanwhile, the HA/MgO-H scaffold gradually formed a tough hydrogel with G' of more than 1000 Pa after hydration, and its high hydration swelling ratio was still retained. Moreover, after the chemical degradation of the dispersed MgO nanocrystals, slow release of Mg2+ from the hydrogel matrix was achieved for up to 8 weeks because of the chelation between Mg2+ and the carboxyl groups of PGA-Cys. In vitro cell studies showed that the HA/MgO-H scaffold could not only effectively promote the migration and proliferation of BMSCs but could also induce osteogenic differentiation. Moreover, in the 8th week after implanting the HA/MgO-H scaffold into femur bone defect zones of DM rats, more effective bone repair was presented by micro-CT imaging. The bone mineral density (397.22 ± 16.36 mg cm-3), trabecular thickness (0.48 ± 0.07 mm), and bone tissue volume/total tissue volume (79.37 ± 7.96%) in the HA/MgO-H group were significantly higher than those in the other groups. Moreover, higher expression of COL-I and OCN after treatment with HA/MgO-H was also displayed. The bone repair mechanism of the HA/MgO-H scaffold was highly associated with reduced infiltration of pro-inflammatory macrophages (CD80+) and higher angiogenesis (CD31+). Collectively, the HA/MgO-H scaffold without the usage of bioactive factors may be a promising biomaterial to accelerate bone defect healing under diabetes mellitus.

Bioinspired biliverdin/silk fibroin hydrogel for antiglioma photothermal therapy and wound healing.

Rationale: Photothermal therapy employs the photoabsorbers to generate heat under the near-infrared (NIR) irradiation for thermal tumor ablation. However, NIR irradiation might damage the adjacent tissue due to the leakage of the photoabsorbers and the residual materials after treatment might hinder the local healing process. A bifunctional hydrogel that holds both photothermal property and potent pro-healing ability provides a viable option to resolve this issue. Methods: In this study, we developed a bioinspired green hydrogel (BVSF) with the integration of bioproduct biliverdin into natural derived silk fibroin matrix for antiglioma photothermal therapy and wound healing. Results: The BVSF hydrogel possessed excellent and controllable photothermal activity under NIR irradiation and resulted in effective tumor ablation both in vitro and in vivo. Additionally, the BVSF hydrogel exerted anti-inflammatory effects both in vitro and in vivo, and stimulated angiogenesis and wound healing in a full-thickness defect rat model. Conclusion: Overall, this proof-of-concept study was aimed to determine the feasibility and reliability of using an all-natural green formulation for photothermal therapy and post-treatment care.

Silk Fibroin-Modified Disulfiram/Zinc Oxide Nanocomposites for pH Triggered Release of Zn2+ and Synergistic Antitumor Efficacy.

Disulfiram (DSF) is an FDA-approved anti-alcoholic drug that has recently proven to be effective in cancer treatment. However, the short half-life in the bloodstream and the metal ion-dependent antitumor activity significantly limited the further application of DSF in the clinical field. To this end, we constructed a silk fibroin modified disulfiram/zinc oxide nanocomposites (SF/DSF@ZnO) to solubilize and stabilize DSF, and, more importantly, achieve pH triggered Zn2+ release and subsequent synergistic antitumor activity. The prepared SF/DSF@ZnO nanocomposites were spherical and had a high drug loading. Triggered by the lysosomal pH, SF/DSF@ZnO could induce the rapid release of Zn2+ under the acidic conditions and caused nanoparticulate disassembly along with DSF release. In vitro experiments showed that cytotoxicity of DSF could be enhanced by the presence of Zn2+, and further amplified when encapsulated into SF/DSF@ZnO nanocomposites. It was confirmed that the significantly amplified cytotoxicity of SF/DSF@ZnO was resulted from pH-triggered Zn2+ release, inhibited cell migration, and increased ROS production. In vivo study showed that SF/DSF@ZnO nanocomposites significantly increased the tumor accumulation and prolonged the retention time. In vivo antitumor experiments in the xenograft model showed that SF/DSF@ZnO exerted the highest tumor-inhibition rate among all the drug treatments. Therefore, this exquisite study established silk fibroin-modified disulfiram/zinc oxide nanocomposites, SF/DSF@ZnO, where ZnO not only acted as a delivery carrier but also served as a metal ion reservoir to achieve synergistic antitumor efficacy. The established DSF nanoformulation displayed excellent therapeutic potential in future cancer treatment.

Tumor cellular membrane camouflaged liposomes as a non-invasive vehicle for genes: specific targeting toward homologous gliomas and traversing the blood-brain barrier.

Gene therapy aimed at malignant gliomas has shown limited success to date due in part to the inability of conventional gene vectors to achieve widespread and specific gene transfer throughout the highly disseminated tumor zone within the brain. Herein, cationic micelles assembled from vitamin E succinate-grafted ε-polylysine (VES-g-PL) polymers were first exploited to condense TRAIL plasmids (pDNA). Thereafter, the condensed pDNA was further encapsulated into liposomes camouflaged with tumor cellular membrane. The condensed pDNA was successfully encapsulated into the inner aqueous compartments of the liposomes instead of the surface, which was proved based on the TEM morphology and decreased cytotoxicity toward HUVEC and PC-12 cells. Moreover, glioma cell membrane (CM) was easily inlaid into the lipid layer of the pDNA-loaded liposomes to form T@VP-MCL, as shown via TEM, AFM, and SDS-PAGE analysis. T@VP-MCL exhibited good particle size stability at strong ion strength and effectively protected pDNA from DNase I induced degradation. Owing to the CM-associated proteins, T@VP-MCL specifically targeted not only ICAM-1 overexpressed in glioma RBMECs but also homogenous glioma cells. Moreover, in vivo imaging showed that T@VP-MCL was effectively located in orthotopic gliomas of rats after intravenous administration, resulting in effective tumor growth inhibition, prolonging the lives of the rats. The mechanism of T@VP-MCL traversing the BBB was highly associated with the down-regulation of the tight junction-associated proteins ZO-1 and claudin-5. Conclusively, T@VP-MCL designed herein may be a potential carrier for therapeutic genes.

Bone-Inspired Tube Filling Decellularized Matrix of Toad Cartilage Provided an Osteoinductive Microenvironment for Mesenchymal Stem Cells to Facilitate the Radius Defect Repair of Rabbit.

Toad bone not only contains the rich cartilage-like matrix but also presents low immunogenicity. It is inferred that decellularized toad bone matrix (dBECM) may provide the more profitable osteoinductive microenvironment for mesenchymal stem cells (MSCs) to promote the repair of bone defects. Herein, a hollow bone-inspired tube is first made from hydroxyapatite (HA) and poly (γ-glutamic acid) (PGA), and then MSCs/dBECM hydrogel is uniformly filled to its central cavity, constructing a biomimetic bone (dBECM + MSCs - PGA + HA). In vitro scratch and transwell experiments show that dBECM hydrogel not only effectively promotes migration and proliferation of MSCs but also induces their osteogenic differentiation. Moreover, the less inflammatory macrophages infiltrate at rat skin after subcutaneously injecting dBECM hydrogel, indicating its low potential for inflammatory attack. After implanting dBECM + MSCs - PGA + HA to critical radius defect of rabbit, X-ray and CT imaging shows that the cortex is effectively regenerated and the medullary cavity recanalization is completed at 20 weeks. Moreover, the expression of Collagen-II and OCN are obviously increased in the defect after implanting dBECM + MSCs - PGA + HA. The therapeutic mechanism of dBECM + MSCs - PGA + HA scaffold are highly associated with the enhanced angiogenesis. Collectively, the biomimetic dBECM + MSCs - PGA + HA scaffold may be a promising strategy to improve radius defect healing efficiency.

Protective effects and mechanisms of bilirubin nanomedicine against acute pancreatitis.

Acute pancreatitis (AP) is a sudden inflammatory reaction, caused by the activation of pancreatic enzymes in the pancreas, and in severe cases can lead to systemic inflammation and multiple organ failure. Oxidative stress contributed to the further deterioration of inflammation and played an important role in AP development. Bilirubin has been found to exert antioxidative, anti-inflammatory, and anti-apoptotic effects in a series of diseases accompanied by a high level of oxidative stress. However, the therapeutic effects of bilirubin for AP management have not yet been demonstrated. Additionally, the poor solubility and potential toxicity of bilirubin also limit its application. Thus, we developed bilirubin encapsulated silk fibrin nanoparticles (BRSNPs) to study the protective effects and mechanisms of bilirubin nanomedicine for the treatment of AP. BRSNPs could selectively delivery to the inflammatory lesion of the pancreas and release bilirubin in an enzyme-responsive manner. In the model of AP caused by L-Arginine hyperstimulation, BRSNPs exerted strong therapeutic effects against AP by the reduction of oxidative stress, decreased expression of pro-inflammatory cytokines, and impaired recruitment of macrophages and neutrophils. The mechanism study indicated that BRSNPs protected acinar cells against extensive oxidative damage and inflammation through inhibiting NF-κB pathway and activating the Nrf2/HO-1 pathway. Collectively, for the first time, this study demonstrated that bilirubin nanomedicine, BRSNPs, are effective in alleviating experimental acute pancreatitis, and the mechanisms are associated with its inhibition of NF-κB regulated pro-inflammatory signaling and activation of Nrf2-regulated cytoprotective protein expression.

Aloe/poloxamer hydrogel as an injectable ß-estradiol delivery scaffold with multi-therapeutic effects to promote endometrial regeneration for intrauterine adhesion treatment.

Intrauterine adhesion (IUA) is characterized by endometrial stromal replaced with fibrous tissue during the trauma or operation induced injury. Current clinic IUA management mainly involves surgical removal of the connective tissues and physical separation and often results in reoccurrence. It is of clinic interest to directly address the issue via facilitating the endometrial repair and thereby inhibiting the formation of re-adhesion. To this end, we designed a nanocomposite aloe/poloxamer hydrogel for ß-estradiol (E2) intrauterine delivery to exert multi-therapeutic effects and promote endometrial regeneration for IUA treatment. Nanoparticulate decellularized uterus (uECMNPs) was prepared to encapsulate E2 (E2@uECMNPs), which improved the solubility and prolonged cargo release. Then, E2@uECMNPs were further embedded into the thermosensitive aloe-poloxamer hydrogel (E2@uECMNPs/AP). Multiple components from E2@uECMNPs/AP system could collectively promote proliferation and inhibit apoptosis of endometrial stromal cells. E2@uECMNPs/AP significantly increased morphological recovery and decreased uterine fibrosis rate compared with IUA rats in other groups in vivo. Additionally, the levels of Ki67, cytokeratin, and estrogen receptor ß were all up-regulated, along with the decreased expression of TGF-ß1 and TNF-α in the uterus from rats receiving E2@uECMNPs/AP therapy. Taken together, in situ administration of E2@uECMNPs/AP hydrogel could effectively promote endometrial regeneration and prevent the re-adhesion.

c(RGDyk)-modified nanoparticles encapsulating quantum dots as a stable fluorescence probe for imaging-guided surgical resection of glioma under the auxiliary UTMD.

Surgical resection remains the preferred approach for some patients with glioblastoma (GBM), and eradication of the residual tumour niche after surgical resection is very helpful for prolonging patient survival. However, complete surgical resection of invasive GBM is difficult because of its ambiguous boundary. Herein, a novel targeting material, c(RGDyk)-poloxamer-188, was synthesized by modifying carboxyl-terminated poloxamer-188 with a glioma-targeting cyclopeptide, c(RGDyk). Quantum dots (QDs) as fluorescent probe were encapsulated into the self-assembled c(RGDyk)-poloxamer-188 polymer nanoparticles (NPs) to construct glioma-targeted QDs-c(RGDyk)NP for imaging-guided surgical resection of GBM. QDs-c(RGDyk)NP exhibited a moderate hydrodynamic diameter of 212.4 nm, a negative zeta potential of -10.1 mV and good stability. QDs-c(RGDyk)NP exhibited significantly lower toxicity against PC12 and C6 cells and HUVECs than free QDs. Moreover, in vitro cellular uptake experiments demonstrated that QDs-c(RGDyk)NP specifically targeted C6 cells, making them display strong fluorescence. Combined with ultrasound-targeted microbubble destruction (UTMD), QDs-c(RGDyk)NP specifically accumulated in glioma tissue in orthotropic tumour rats after intravenous administration, evidenced by ex vivo NIR fluorescence imaging of bulk brain and glioma tissue sections. Furthermore, fluorescence imaging with QDs-c(RGDyk)NP guided accurate surgical resection of glioma. Finally, the safety of QDs-c(RGDyk)NP was verified using pathological HE staining. In conclusion, QDs-c(RGDyk)NP may be a potential imaging probe for imaging-guided surgery.

Localized Controlled Release of Bilirubin from ß-Cyclodextrin-Conjugated ε-Polylysine To Attenuate Oxidative Stress and Inflammation in Transplanted Islets.

Islet transplantation has been considered the most promising therapeutic option with the potential to restore the physiological regulation of blood glucose concentrations in type 1 diabetes treatment. However, islets suffer from oxidative stress and nonspecific inflammation in the early stage of transplantation, which attributed to the leading cause of islet graft failure. Our previous study reported that bilirubin exerted antioxidative and anti-inflammatory effects on hypothermic preserved islets, which inspire us to utilize bilirubin to address the survival issue of grafted islets. However, the application of bilirubin for islet transplantation is limited by its poor solubility and fast clearance. In this study, we designed a supramolecular carrier (PLCD) that could improve the solubility of bilirubin and slowly release bilirubin to protect islets after cotransplantation. PLCD was synthesized by conjugating activated ß-cyclodextrin (ß-CD) to the side chain of ε-polylysine (PLL) and acted as a carrier to load bilirubin via host-guest interactions. The constructed bilirubin supramolecular system (PLCD-BR) significantly improved the solubility and prolonged the action time of bilirubin. In vitro results confirmed that PLCD-BR coculture substantially enhanced the resistance of islets to excessive oxidative stress and proinflammatory stimulation and maximumly maintained the islet function. In vivo, PLCD could prolong drug duration at the transplant site, and the localized released bilirubin could protect the islets from oxidative stress and suppress the production of inflammatory cytokines. Crucially, islet transplantation with PLCD-BR significantly extended the stable blood glucose time of diabetic mice and produced a faster glucose clearance compared to those cotransplanted with free bilirubin. Additionally, immunohistochemical analysis showed that PLCD-BR had superior antioxidative and anti-inflammatory abilities and beneficial effects on angiogenesis. These findings demonstrate that the PLCD-BR has great potentials to support successful islet transplantation.

In vitro and in vivo evaluation of didymin cyclodextrin inclusion complexes: characterization and chemosensitization activity.

Didymin is a dietary flavonoid that first found in citrus fruits, and possesses antioxidant properties. Our preliminary experiments first discovered that didymin was able to sensitize the resistant cancer cells against chemotherapeutics and combat multidrug resistance. However, its poor aqueous solubility and resultant low bioavailability limit its potentials as an adjuvant phytochemical drug for chemotherapy. Thus, this study prepared the inclusion complex of didymin with ß-cyclodextrin and 2-hydroxypropyl-ß-cyclodextrin to improve its bioavailability and then evaluate their chemosensitization effects. The didymin inclusion complexes formulation was prepared and their host-guest structure was characterized by FT-IR, PXRD, DSC, and SEM techniques. In vitro/in vivo results demonstrated that didymin inclusion complex enhanced its water solubility and orally bioavailability. Furthermore, didymin inclusion complex exerted considerable chemosensitivity potency, and improve the anti-tumor effects of chemotherapeutics in vivo. Therefore, didymin inclusion complex could provide a safe, effective, economical, and adjuvant drug for future treatment of chemoresistant cancers.

Exploiting crosslinked decellularized matrix to achieve uterus regeneration and construction.

Decellularized extracellular matrix (dECM) has been considered as a promising scaffold in xenotransplantation, yet natural tissue dECM is often mechanically weak and rapidly degraded, compromising the outcomes. How to restore the mechanical strength and optimise the in vivo degradation, but maintain the microstructure and maximumly suppress the immune rejection, remains challenging. For this aim, we prepared and characterised various crosslinked decellularized rabbit uterus matrix (dUECM) and evaluated in vivo performance after uterus xenotransplantation from rabbit to rat. Naturally derived genipin (GP) and procyanidins (PC) were chosen to crosslink the dUECM, producing significant mechanical enhanced crosslinked-dUECM along with prolonged enzymatic degradation rate. Xenogeneic subcutaneous graft studies revealed that PC- and GP-crosslinked dUECM experienced significant cell infiltration and caused low immune reactions, indicating the desired biocompatibility. In vivo transplantation of GP- and PC-crosslinked dUECM to a uterus circular excised rat yielded excellent recellularization ability and promoted uterus regeneration after 90 days. While the reconstruction efficacy of crosslinked dUECM is highly depended on the crosslinking degree, crosslinking condition must be carefully evaluated to balance the role of crosslinked dECM in mechanical and biological support for tissue regeneration promotion.

Cross-linked nanoparticles of silk fibroin with proanthocyanidins as a promising vehicle of indocyanine green for photo-thermal therapy of glioma.

Instability of silk fibroin nanoparticles (SFNPs) in physiologic condition hinders its application as drug delivery vehicle. Herein, indocyanine green (ICG) loaded silk fibroin nanoparticles (ICG-SFNPs) was firstly prepared and then crosslinked by proanthocyanidins to obtain the stable ICG-CSFNPs for killing the residual tumour niche under near infra-red irradiation (NIR) after surgery. The particle size and zeta potentials of ICG-CSFNPs was 120.1 nm and -40.4 mV, respectively. Moreover, ICG-CSFNPs exhibited good stability of particle size in the physiological medium. Meanwhile, the stable photothermal properties of ICG-CSFNPs were not compromised even after several cycles of NIR. Few of the ICG-CSFNPs were phagocytized by RAW264.7 macrophage in vitro, while they were easily internalized by C6 glioma cells, resulting in their significant toxicity on tumour cells after NIR. The pharmacokinetic study showed that ICG-CSFNPs had a longer blood circulation time than ICG-SFNPs, making them more distribution in glioma after intravenous administration in vivo. Meanwhile, the pharmacological study showed the more effective inhibition of tumour growth was exhibited by ICG-CSFNPs in C6 glioma-bearing mice after NIR. Overall, the cross-linked nanoparticles of silk fibroin may be a promising vehicle of ICG for photothermal therapy of glioma after surgical resection.

Recent development and biomedical applications of decellularized extracellular matrix biomaterials.

Decellularized matrix (dECM) is isolated extracellular matrix of tissues from its original inhabiting cells, which has emerged as a promising natural biomaterial for tissue engineering, aiming at support, replacement or regeneration of damaged tissues. The dECM can be easily obtained from tissues/organs of various species by adequate decellularization methods, and mimics the structure and composition of the native extracellular matrix, providing a favorable cellular environment. In this review, we summarize the recent developments in the preparation of dECM materials, including decellularization, crosslinking and sterilization. Also, we cover the advances in the utilization of dECM biomaterials in regeneration medicine in pre-clinic and clinical trials. Moreover, we highlight those emerging medical benefits of dECM beyond tissue engineering, such as cell transplantation, in vitro/in vivo model and therapeutic cues delivery. With the advances in the preparation and broader application, the dECM biomaterials could become the gold scaffold and pharmaceutical excipients in medical sciences.

Bilirubin Improves the Quality and Function of Hypothermic Preserved Islets by Its Antioxidative and Anti-inflammatory Effect.

BACKGROUND: Islet transplantation is a promising option for the treatment of type 1 diabetes. However, the current lack of practical techniques for the isolated islets preservation still hampers the advancement of life-saving islet transplantation. Islet suffers from internal or external stimuli-induced oxidative stress and subsequent inflammation during preservation, which leads to disappointing outcomes regarding islet yield, survival, and function. Reactive oxygen species (ROS) overproduction is the primary cause of oxidative stress that induces islet loss and dysfunction. Thus, in this article, we hypothesized that an endogenous antioxidant, bilirubin, that could efficiently scavenge ROS and inhibit inflammatory reactions could be beneficial for islet preservation. METHODS: Herein, we studied the effect of bilirubin on the hypothermic preserved (4°C) islets and evaluate the islets viability, insulin secretory function, oxidative stress levels, and in vivo transplantation performance. RESULTS: Bilirubin could prevent cellular damages during short-term preservation and maintain the cocultured islets viability and function. The protective role of bilirubin is associated with its antioxidative ability, which dramatically increased the activities of antioxidant enzymes (superoxide dismutase and glutathione peroxidase) and decreased the levels of ROS and malondialdehyde. Diabetic mice transplanted with bilirubin preserved islets were normoglycemic for 28 days, even overmatched the diabetic mouse transplanted with fresh islets. Mice receiving bilirubin cocultured islets required the least time to achieve normoglycemia among all groups and exhibited minimum inflammatory responses during the early transplantation stage. CONCLUSIONS: By utilizing bilirubin, we achieved highly viable and functional islets after hypothermic preservation to reverse diabetes in mice.