Preparation Of Antibacterial Hyaluronic Acid Gel And Its Application In The Treatment Of Acne

Acne is a common chronic inflammatory disease of hair follicles and sebaceous glands in adolescents.The occurrence of acne is closely related to sebum oversecretion,sebaceous duct blockage of hair follicles,bacterial infection and inflammation.Excessive secretion of sebum from sebaceous glands causes clog of pores and promotes the proliferation of the gram-positive anaerobic bacteria PRO pionibacterium acnes（P.acnes）,which causes skin inflammation to form acne.So many studies have looked at treating inflammatory acne by eliminating P.acnes.Treatments for acne include oral therapy and percutaneous medication are widely used because of their ability to avoid organ damage to a greater extent than oral treatment.Commonly used antibacterial drugs for acne can be divided into antibiotics and antibacterial agents.However,long-term use of antibiotics will cause bacteria to form drug-resistant bacteria and have large side effects.In contrast,antibacterial treatment is more favored by researchers.Recent studies have shown that hyaluronic acid（HA）is a good natural free radical scavenger,protecting cell tissue from free radical damage,avoiding lipid peroxidation,helping to reduce skin damage and improve skin effect.Based on this,this project planned to use cross-linked HA as drug delivery carrier to prepare gel with antibacterial properties combining with the properties of lauric acid（LA）or chitosan（CS）that can kill P.acnes.Using cysteamine（Cys）which is sensitive to ROS,functionalized HA derivatives（HA-Cys）were prepared by an amine-carboxyl amidation reaction.On the one hand,gel was formed by chemical reaction with HA and 1,4 butanediol diglycidyl ether（BDDE）with high molecular weight.Further,LA was embedded in the gel network structure.On the other hand,HA-Cys and CS were aminated to form gel.The chemical structure and network structure of cHA-Cys@LA and Cys-HA-CS were characterized by infrared spectroscopy（FTIR）,scanning electron microscopy（SEM）and Rotary rheometer.Cytotoxicity results showed that cHA-Cys@LA and Cys-HA-CS gel were less toxic to normal cells.It was proved that cHA-Cys@LA and Cys-HA-CS gel had a good inhibitory effect on P.acnes by plate counting.In vitro degradation experiments showed that cHA-Cys@LA and Cys-HA-CS gel were degraded in 12 and20 days,respectively.By testing the redox responsiveness of cHA-Cys@LA and Cys-HA-CS gels,it was found that the gels degraded faster in PBS solutions containing Hydrogen peroxide（H₂O₂）（1 m M or 10 m M）.This combination of antibacterial agents and anti-free radical synergistic treatment of acne,improves the treatment of acne has a great application prospect.