Preparation Of Polyaniline-based Photothermal Framework Hydrogel And Its Integrated Treatment For Postoperative Tumors

The main treatment method for melanoma in clinical practice is surgical resection.However,the high invasiveness of melanoma can lead to residual tumor tissue recurrence at the wound site after surgery.During postoperative chemotherapy and radiotherapy,there are problems such as drug resistance and toxic side effects.In addition to the problem of postoperative recurrence,microbial infection can also have a serious impact on the process of repairing skin defects after surgery,which may lead to a series of complications.In order to address the above-mentioned issues,we have developed a multifunctional poly(aniline)-based photothermal hydrogel scaffold that combines anti-recurrence,anti-infection and pro-healing properties for postoperative treatment of residual melanoma cells and infected wounds.The main content of this paper can be summarized into three parts:(1)Firstly,chitosan was chemically modified by introducing sulfonic acid groups to obtain sulfonated chitosan(SCS).Then,aniline(AN)was grafted onto SCS to synthesize water-soluble sulfonated chitosan-polyaniline(SCS-PANI)gel scaffold.The Schiff base and metal coordination dual dynamic crosslinking were constructed between the protocatechuic aldehyde(Pa),trivalent iron ions(Fe),and SCS-PANI to form a hydrogel scaffold(SCS-PANI/Pa@Fe).Based on the reversibility of dual dynamic covalent bonds,the hydrogel scaffold has excellent self-healing,injectability and degradability.The presence of PANI and Pa in the photothermal scaffold endows the hydrogel with antioxidant capacity.The sulfonic acid groups in SCS have a selfdoping effect on PANI,which shifts the absorption peak to the near-infrared region and endows it with p H responsiveness and photothermal conversion ability upon nearinfrared light excitation(η = 48.1%).(2)The SCS-PANI/Pa@Fe/DOX hydrogel exhibits photo-controlled drug release properties and can achieve synergistic anti-tumor effects with PTT.The SCSPANI/Pa@Fe hydrogel shows good cell compatibility(L929 cell viability > 90%)and blood compatibility(less than 5%).After irradiation with an 808 nm laser,the SCSPANI/Pa@Fe/DOX hydrogel showed excellent synergistic therapeutic effects,and the survival rate of tumor cells was only 2.89%.In addition,the hydrogel also exhibited good antibacterial activity and has potential applications in anti-bacterial treatment of infected wounds.(3)In order to investigate the effect of SCS-PANI/Pa@Fe/DOX hydrogel on postoperative tumor recurrence and promotion of wound healing,it was first demonstrated through mouse tail amputation and liver bleeding models that the hydrogel has hemostatic activity.Subsequently,in vivo anti-tumor recurrence test results showed that under 808 nm laser irradiation,the photothermal-chemotherapy synergistic treatment can effectively inhibit tumor recurrence and promote postoperative wound healing.In addition,SCS-PANI/Pa@Fe hydrogel showed significant effects in promoting wound healing of Staphylococcus aureus-infected wounds.In summary,SCS-PANI/Pa@Fe hydrogel can prevent postoperative residual tumor recurrence while also having the ability to prevent wound infection and promote wound healing.Additionally,it provides an effective solution for postoperative treatment repair and skin regeneration in other superficial cancers.