An antibacterial and anti-oxidant hydrogel containing hyperbranched poly-l-lysine and tea polyphenols accelerates healing of infected wound.

Both bacteria-infection and excessive inflammation delay the wound healing process and even create non-healing wound, thus it is highly desirable to endow the wound dressing with bactericidal and anti-oxidation properties. Herein an antibacterial and antioxidation hydrogel based on Carbomer 940 (CBM) and hydroxypropyl methyl cellulose (HPMC) loaded with tea polyphenols (TP) and hyperbranched poly-l-lysine (HBPL) was designed and fabricated. The hydrogel killed 99.9 % of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) at 107 CFU mL-1, and showed strong antioxidation against H2O2 and 2,2-di(4-tert-octylphenyl)-1-picryl-hydrazyl (DPPH) radicals without noticeable cytotoxicity in vitro. The CBM/HPMC/HBPL/TP hydrogel significantly shortened the inflammatory period of the MRSA-infected full-thickness skin wound of rats in vivo, with 2 orders of lower MRSA colonies compared with the blank control, and promoted the wound closure especially at the earlier stage. The inflammation was suppressed and the vascularization was promoted significantly as well, resulting in reduced pro-inflammatory factors including interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), and increased anti-inflammatory factors such as interleukin-4 (IL-4) and interleukin-10 (IL-10).

A tough, antibacterial and antioxidant hydrogel dressing accelerates wound healing and suppresses hypertrophic scar formation in infected wounds.

Wound management is an important issue that places enormous pressure on the physical and mental health of patients, especially in cases of infection, where the increased inflammatory response could lead to severe hypertrophic scars (HSs). In this study, a hydrogel dressing was developed by combining the high strength and toughness, swelling resistance, antibacterial and antioxidant capabilities. The hydrogel matrix was composed of a double network of polyvinyl alcohol (PVA) and agarose with excellent mechanical properties. Hyperbranched polylysine (HBPL), a highly effective antibacterial cationic polymer, and tannic acid (TA), a strong antioxidant molecule, were added to the hydrogel as functional components. Examination of antibacterial and antioxidant properties of the hydrogel confirmed the full play of the efficacy of HBPL and TA. In the in vivo studies of methicillin-resistant Staphylococcus aureus (MRSA) infection, the hydrogel had shown obvious promotion of wound healing, and more profoundly, significant suppression of scar formation. Due to the common raw materials and simple preparation methods, this hydrogel can be mass produced and used for accelerating wound healing while preventing HSs in infected wounds.

A broad-spectrum antibacterial and tough hydrogel dressing accelerates healing of infected wound in vivo.

Infection can disturb the wound healing process and lead to poor skin regeneration, chronic wound, septicemia and even death. To combat the multi-drug resistance bacteria or fungi, it is urgent and necessary to develop advanced antimicrobial wound dressings. In this study, a composite hydrogel dressing composed of polyvinyl alcohol (PVA), agarose, glycerol and antibacterial hyperbranched polylysine (HBPL) was prepared by a freeze-thawing method. The hydrogel showed robust mechanical properties, and the HBPL in the hydrogel displayed effective and broad-spectrum antimicrobial properties to bacteria and fungi as well as biofilms. The composite hydrogel exhibited good biocompatibility with respect to the levels of cells, blood, tissue and main organs. In an animal experiment of an infected wound model, the hydrogel significantly eliminated the infection and accelerated the wound regeneration with better tissue morphology and angiogenesis. The hydrogel also successfully achieved scalable production of over 600 g with a yield over 90 %, suggesting the great potential for the application in practice.

Biomedical polymers: synthesis, properties, and applications.

Biomedical polymers have been extensively developed for promising applications in a lot of biomedical fields, such as therapeutic medicine delivery, disease detection and diagnosis, biosensing, regenerative medicine, and disease treatment. In this review, we summarize the most recent advances in the synthesis and application of biomedical polymers, and discuss the comprehensive understanding of their property-function relationship for corresponding biomedical applications. In particular, a few burgeoning bioactive polymers, such as peptide/biomembrane/microorganism/cell-based biomedical polymers, are also introduced and highlighted as the emerging biomaterials for cancer precision therapy. Furthermore, the foreseeable challenges and outlook of the development of more efficient, healthier and safer biomedical polymers are discussed. We wish this systemic and comprehensive review on highlighting frontier progress of biomedical polymers could inspire and promote new breakthrough in fundamental research and clinical translation.