Incorporation of ROS-Responsive Substance P-Loaded Zeolite Imidazolate Framework-8 Nanoparticles into a Ca2+-Cross-Linked Alginate/Pectin Hydrogel for Wound Dressing Applications.

PURPOSE: Wound healing, especially of extensive full-thickness wounds, is one of the most difficult problems in clinical studies. In this study, we prepared a novel substance P (SP)-delivery system using zeolite imidazolate framework-8 (ZIF-8) nanoparticles. METHODS: We synthesized ZIF-8 nanoparticles using a modified biomimetic mineralization method. We then coated SP-loaded ZIF-8 nanoparticles (SP@ZIF-8) with polyethylene glycol-thioketal (PEG-TK) to fabricate SP@ZIF-8-PEG-TK nanoparticles, and encapsulated them in injectable hydrogel composed of sodium alginate and pectin and cross-linked using calcium chloride. The final hydrogel wound dressing containing SP@ZIF-8-PEG-TK nanoparticles was called SP@ZIF-8-PEG-TK@CA. RESULTS: The fabricated ZIF-8 nanoparticles had high SP-loading efficiency. SP-release assay showed that the SP@ZIF-8-PEG-TK nanoparticles maintained drug activity and showed responsive release under stimulation by reactive oxygen species. The SP@ZIF-8-PEG-TK nanoparticles promoted proliferation of human dermal fibroblasts, up-regulated expression levels of inflammation-related genes in macrophages, and exhibited favorable cytocompatibility in vitro. Full-thickness excision wound models in vivo confirmed that SP@ZIF-8-PEG-TK@CA dressings had excellent wound-healing efficacy by promoting an early inflammatory response and subsequent M2 macrophage polarization in the wound-healing process. CONCLUSION: In conclusion, these findings indicated that SP@ZIF-8-PEG-TK@CA dressings might be useful for wound dressing applications in the clinic.

Ligno(hemi)cellulolytic Enzyme Profiles during the Developmental Cycle of the Royal Oyster Medicinal Mushroom Pleurotus eryngii (Agaricomycetes) Grown on Supplemented Agri-Wastes.

We have determined the production profiles of major ligno(hemi)cellulolytic enzymes at different stages of the mushroom development cycle during industrial scale cultivation of Pleurotus eryngii on supplemented agri-wastes. Endo-1,4-ß-glucanase, cellobiohydrolase and endoxylanase levels remained relatively low during substrate colonization, increased sharply when small fruit bodies appeared, and peaked at maturation. ß-Glucosidase and ß-xylosidase levels decreased when substrate colonization was complete, increased with the appearance of small fruit bodies and primordia, respectively, and reached maxima at maturation. Laccase peaked along with substrate colonization but, after falling sharply in the upper substrate layers, remained relatively low until postinduction. Levels increased slightly when primordia appeared, fell to minimal values during the small and mature fruit body stages, and increased again postharvest. Manganese peroxidase (Mn-P) exhibited a similar pattern initially but high enzyme levels also coincided with primordia formation. Laccase and Mn-P activity patterns were compatible with a lignin-degradation function associated with substrate colonization and, in the former case, a putative role in fruit body morphogenesis. Based on the relatively low levels of polysaccharidases recorded during the initial stages of substrate colonization, we conclude that reducing sugar levels in noncolonized substrate were adequate for sustainable vegetative growth at that stage. We further conclude that the increase in enzyme production later in the developmental cycle was consistent with the replenishment of depleted reducing sugar from cellulose in the growth substrate to levels required for fruit body formation. These data provide new information describing combined temporal and spatial enzyme production profiles throughout the mushroom development cycle under a set of conditions used in industrial scale production.

The protective role of autophagy in experimental osteoarthritis, and the therapeutic effects of Torin 1 on osteoarthritis by activating autophagy.

BACKGROUND: Recent studies have shown that autophagy was associated with the development of osteoarthritis (OA), the purpose of this research was to determine the exact role of autophagy in OA and investigate effective therapeutic drugs to inhibit the pathological progression of OA. METHODS: In this study, a cellular OA model was generated by stimulating SW1353 cells with IL-1ß and a rabbit OA model was established by intra-articular injection of collagenase, followed by treatment with Torin 1 or 3-Methyladenine (3-MA). The mRNA expression levels of VEGF, MMP-13 and TIMP-1 were determined by quantitative real-time PCR. The caitilage degeneration was examined by histological evaluation, chondrocytes degeneration and autophagosomes were observed by transmission electron microscopy. Expression levels of Beclin-1 and LC3 were evaluated by western blotting and immunofluorescence. RESULTS: The degeneration of SW 1353 cells, cartilage and chondrocytes was related to the loss of autophagy in experimental OA. 3-MA increased the severity of degeneration of cells and cartilage by autophagy inhibition, while Torin 1 reduced that by autophagy activation. CONCLUSIONS: The loss of autophagy is linked with the experimental OA and autophagy may play a protective role in the pathogenesis of OA. Treatment of Torin 1 can inhibit the degenerative changes of experimental OA by activating autophagy and it may be a useful therapeutic drug for OA.

Photochemical tissue bonding: a potential strategy for treating limbal stem cell deficiency.

BACKGROUND AND OBJECTIVE: To determine the feasibility of attaching human amniotic membrane (HAM), pre-cultured with limbal stem cells (LSCs), to cornea using a novel, light-activated tissue bonding method. MATERIALS AND METHODS: LSCs were isolated from rabbit eyes, and then cultured on de-epithelialized HAM to create grafts (HAM/LSC). These were then transplanted onto rabbit eyes with surgically created limbal stem cell deficiency (LSCD). The grafts were secured either by sutures or by a light-activated method called photochemical tissue bonding (PTB). Outcomes included corneal opacity, inflammation, neovascularization, and collagen alignment. RESULTS: The isolated and cultured cells were verified to be LSCs based on their K19+/intergrin ß1+/P63+/K3 profile. Securing the HAM/LSC graft with PTB provided better outcomes. At 28 days post-surgery, the corneal opacity scores were significantly lower after securing the graft with PTB compared with suture attachment (0.8 ± 0.5 vs. 1.8 ± 0.5, P < 0.01). Similarly, neovascularization scores were lower after PTB (0.8 ± 0.5 vs. 1.5 ± 0.6, P < 0.01). Quantification of MPO and CD31 levels from immunofluorecent staining indicated that PTB stimulated less neutrophil infiltration (5.3 ± 2.2 vs. 13.3 ± 3.1, P < 0.01) and less new blood vessels formation (2.0 ± 0.8 vs. 6.3 ± 1.3, P < 0.01) at the wound site. The collagen alignment in PTB-treated corneas, as shown by immunofluorescence and second harmonic generation image, was better organized in the PTB-treated group than in the suture group. CONCLUSION: Bonding LSC grafts with PTB produced improved outcomes compared to suture attachment. This light-activated method is a promising modality for treating patients with LSCD.