Preparation of physically crosslinked PVA/HLC/SA hydrogel and exploration of its effects on full-thickness skin defects

Screening of Short-Chain Antimicrobial Peptide LKARI with Broad-Spectrum Bactericidal Properties and Its Application in Promoting Wound Healing

Due to the extensive use of antibiotics, many highly resistant bacteria and extensively resistant bacteria have been produced. In recent years, the increase of drug-resistant bacteria and the resulting proliferation of drug-resistant bacteria have increased the incidence of hospital-acquired infections and caused great harm to human health. Antimicrobial peptides (AMPs) are considered to be an innovative antibiotic and belong to the latest advances in this field. We designed a polypeptide and verified its low minimum inhibitory concentration and broad-spectrum activity against Gram-positive bacteria, Gram-negative bacteria, and fungi in microbiology and pharmacology. Several experiments have confirmed that the screened antimicrobial peptides have significant antidrug resistance and also show significant therapeutic properties in the treatment of systemic bacterial infections. In addition, through our experimental research, it was proved that the antibacterial hydrogel composed of poly(vinyl alcohol), sodium alginate, and antimicrobial peptides had excellent antibacterial properties and showed good wound healing ability.

Conductive interpenetrating network organohydrogels of gellan gum/polypyrrole with weather-tolerance, piezoresistive sensing and shape-memory capability

To develop ecofriendly multifunctional gel materials for sustainable flexible electronic devices, composite organohydrogels of gellan gum (GG) and polypyrrole (PPy) with an interpenetrating network structure (IPN-GG/PPy organohydrogels) were developed first time, through fabrication of GG organohydrogels followed by in-situ oxidation polymerization of pyrrole inside. Combination of water with glycerol can not only impart environment-stability to GG hydrogels but promote the mechanics remarkably, with the compressive strength amplified by 1250 % from 0.02 to 0.27 MPa. Incorporation of PPy confers electrical conductivity to the GG organohydrogel as well as promoting the mechanical performance further. The maximum conductivity of the IPN-GG/PPy organohydrogels reached 1.2 mS/cm at 25 °C, and retained at 0.6 mS/cm under -20 °C and 0.56 mS/cm after 7 days' exposure in 25 °C and 60 % RH. The compression strength of that with the maximum conductivity increases by 170 % from 0.27 to 0.73 MPa. The excellent conductivity and mechanical properties endow the IPN-GG/PPy organohydrogels good piezoresistive strain/pressure sensing behavior. Moreover, the thermo-reversible GG network bestows them shape-memory capability. The multifunctionality and intrinsic eco-friendliness is favorable for sustainable application in fields such as flexible electronics, soft robotics and artificial intelligence, competent in motion recognition, physiological signal monitoring, intelligent actuation.

Evaluation of immobilized microspheres of Clonostachys rosea on Botrytis cinerea and tomato seedlings

Tomato (Solanum lycopersicum L.) is a popular vegetable crop which is widely cultivated around the world. However, the production of tomatoes is threatened by several phytopathogenic agents, including gray mold (Botrytis cinerea Pers.). Biological control using fungal agents such as Clonostachys rosea plays a pivotal role in managing gray mold. However, these biological agents can negatively be influenced by environmental factors. However, immobilization is a promising approach to tackle this issue. In this research, we used a nontoxic chemical material, sodium alginate as a carrier to immobilize C. rosea. For this, sodium alginate microspheres were prepared using sodium alginate prior to embedding C. rosea. The results showed that C. rosea was successfully embedded in sodium alginate microspheres, and immobilization enhanced the stability of the fungi. The embedded C. rosea was able to suppress the growth of gray mold efficiently. In addition, the activity of stress related enzymes, peroxidase superoxidase dismutase and polyphenol oxidation was promoted in tomatoes treated with the embedded C. rosea. By measuring photosynthetic efficiency, it was noted that the embedded C. rosea has positive impacts on tomato plants. Taken together, these results indicate that immobilization of C. rosea improved its stability without detrimentally affecting its efficiency on gray mold suppression and tomato growth. The results of this research can be used as a basis for research and development of new immobilized biocontrol agents.

Exploring the potential of the recombinant human collagens for biomedical and clinical applications: a short review

Natural animal collagen and its recombinant collagen are favourable replacements in human tissue engineering due to their remarkable biomedical property. However, this exploitation is largely restricted due to the potential of immunogenicity and virus contamination. Exploring new ways to produce human collagen is fundamental to its biomedical and clinical application. All human fibrillar collagen molecules have three polypeptide chains constructed from a repeating Gly-Xaa-Yaa triplet, where Xaa and Yaa represent one random amino acid. Using cDNA techniques to modify several repeat sequences of the cDNA fragment, a novel human collagen, named recombinant human-like collagen (rHLC), with low immunogenicity and little risk from hidden virus can be engineered and notably tailored to specific applications. Human-like collagen (HLC) was initially used as a coating to modify the tissue engineering scaffold, and then used as the scaffold after cross-link agents were added to increase its mechanical strength. Due to its good biocompatibility, low immunogenicity, stabilised property, and the ability of mass production, HLC has been widely used in skin injury treatments, vascular scaffolds engineering, cartilage, bone defect repair, skincare, haemostatic sponge, and drug delivery, including coating with medical nanoparticles. In this review, we symmetrically reviewed the development, recent advances in design and application of HLC, and other recombinant human collagen-based biomedicine potentials. At the end, future improvements are also discussed.