In situ Hydrogels Prepared by Photo-initiated Crosslinking of Acrylated Polymers for Local Delivery of Antitumor Drugs.

A triblock copolymer was synthesized by ring opening polymerization of ε-caprolactone in the presence of poly(ethylene glycol) (PEG). The resulted PCL-PEG-PCL triblock copolymer, PEG and monomethoxy (MPEG) were functionalized by end group acrylation. NMR and FT-IR analyses evidenced the successful synthesis and functionalization of polymers. A series of photo-crosslinked hydrogels composed of acrylated PEG-PCL-Acr and MPEG-Acr or PEG-Acr were prepared by exposure to visible light using lithium phenyl-2,4,6-trimethylbenzoylphosphinate as initiator. The hydrogels present a porous and interconnected structure as shown by SEM. The swelling performance of hydrogels is closely related to the crosslinking density and hydrophilic content. Addition of MPEG or PEG results in increase in water absorption capacity of hydrogels. In vitro degradation of hydrogels was realized in the presence of a lipase from porcine pancreas. Various degradation rates were obtained which mainly depend on the hydrogel composition. MTT assay confirmed the good biocompatibility of hydrogels. Importantly, in situ gelation was achieved by irradiation of a precursor solution injected in the abdomen of mice. Doxorubicin (DOX) was selected as a model antitumor drug to evaluate the potential of hydrogels in cancer therapy. Drug-loaded hydrogels were prepared by in situ encapsulation. In vitro drug release studies showed a sustained release during 28 days with small burst release. DOX-loaded hydrogels exhibit antitumor activity against A529 lung cancer cells comparable to free drug, suggesting that injectable in situ hydrogel with tunable properties could be most promising for local drug delivery in cancer therapy.

Novel chitosan based metal-organic polyhedrons/enzyme hybrid hydrogel with antibacterial activity to promote wound healing.

This work aimed to develop a novel chitosan based metal-organic polyhedrons (MOPs)/enzyme hybrid hydrogel with superior antimicrobial properties in wound healing treatment. Hybrid hydrogel was prepared by crosslinking glucose oxidase (GOx), vanadium metal-organic polyhedrons (VMOP-2) and chitosan using glutaraldehyde as crosslinker. The formed GVCS hydrogel was characterized by using various techniques, including FTIR, SEM, XPS, TGA and EDX. Data show that GVCS hydrogel was successfully obtained with uniform distribution of GOx and VMOP-2 in the hydrogel structure. Antibacterial tests show that GVCS hydrogel exhibits better bactericidal effect on both gram-negative bacteria (S. aureus) and gram-positive bacteria (E. coli) compared to other hydrogel samples because of its hydroxyl radicals generation capacity in the presence of glucose. MTT assay shows that the hydrogel presents good cell compatibility. In vivo experiments using an infected wound model indicate that GVCS hydrogel can effectively facilitate wound healing. Therefore, chitosan based MOPs/enzyme hybrid hydrogel could be most promising for antibacterial therapy in clinical applications.

Analysis of Transcriptomic Changes in Bovine Endometrial Stromal Cells Treated With Lipopolysaccharide.

Endometritis adversely affects the ability of cattle to reproduce and significantly reduces milk production. The is mainly composed of epithelial and stromal cells, and they produce the first immune response to invading pathogens. However, most of the epithelial cells are disrupted, and stromal cells are exposed to an inflammatory environment when endometritis occurs, especially postpartum. Many bacteria and toxins start attacking stromal cell due to loss of epithelium, which stimulates Toll-like receptor (TLRs) on stromal cells and causes upregulated expression of cytokines. Understanding the genome-wide characterization of bovine endometritis will be beneficial for prevention and treatment of endometritis. In this study, whole-transcriptomic gene changes in bovine endometrial stromal cells (BESCs) treated with LPS were compared with those treated with PBS (control group) and were analyzed by RNA sequencing. Compared with the control group, a total of 366 differentially expressed genes (DEGs) were identified in the LPS-induced group (234 upregulated and 132 downregulated genes), with an adjusted P < 0.05 by DESeq. Gene Ontology (GO) enrichment analysis revealed that DEGs were most enriched in interleukin-1 receptor binding, regulation of cell activation, and lymphocyte-activated interleukin-12 production. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed DEGs were most enriched in the TNF signaling pathway, Toll-like receptor signaling pathway, cytokine-cytokine receptor interaction, NF-κB signaling pathway, and chemokine signaling pathway. The results of this study unraveled BESCs affected with LPS transcriptome profile alterations, which may have a significant effect on treatment inflammation by comprehending molecular mechanisms and authenticating unique genes related to endometritis.