Dyeing Characteristics of Chitosan Biguanidine Hydrochloride Treated Wool Fabrics

Chitosan biguanidine hydrochloride(CGH) has been synthesized by the guanidineylation reaction of chitosan with dicyandiamide.The structures of CGH were characterized by Fourier transform infrared spectroscopy and 13CNMR spectra.In this paper,we used citric acid(CA) as a crosslinking agent,mixed with CGH to perform a pad-drycure treatment on wool fabric to study reaction mechanism during crosslinking with the help of Fourier transform infrared spectroscopy(FT-IR) and scanning electron microscopy(SEM).Dyeing characteristics of CGH treated wool fabric was assessed.The effects of CGH concentration,curing temperature,dipping time,pH value on color yield of reactive dyes on wool fibres were investigated.Fastness properties of the modified wool fabric to laundering and crocking have also been discussed.Fourier transform infrared spectroscopy(FT-IR) showed that CA produce esterification with the-OH group of the wool and transamidation with the-NH2 group of the CGH to form a crosslink.Scanning electron microscopy(SEM) analysis showed the CGH firmly attached to the surface of wool fibre.It was found that the CGH pretreated wool fabrics had significantly improved dyeability characteristics.It is worthwhile to mention that the CGH treated samples have antibacterial potential due to the antibacterial property of chitosan molecules and guanidinium salts.

Metformin administration in prevention of colorectal polyps in type 2 diabetes mellitus patients

BACKGROUND Colorectal polyps are frequently observed in patients with type 2 diabetes mellitus(DM),posing a significant risk for colorectal cancer.Metformin,a widely prescribed biguanidine drug for type 2 DM,has been suggested to have potential chemoprophylactic effects against various cancers.AIM To explore the correlation between colorectal polyps and metformin use in type 2 DM patients.METHODS Type 2 DM patients were categorized into polyp and non-polyp groups.Following this,all patients were categorized into the type 2 DM-metformin,type 2 DM-non-metformin,and non-type 2 DM groups.Based on the baseline colonoscopy results,we performed pairwise comparisons of the incidence of colorectal polyps among the three groups.Additionally,we analyzed the relationship between colorectal polyps and the duration of metformin use and between the size and number of polyps and metformin use.Simultaneously,we focused on the specific pathological types of polyps and analyzed their relationship with metformin use.Finally,we compared the incidence of polyps between metformin and non-metformin groups according to the interval colonoscopy results.RESULTS The rate of metformin use in patients with colorectal polyps was 0.502 times that of patients without colorectal polyps[odds ratio(OR)=0.502,95%confidence interval(CI):0.365-0.689;P<0.001].The incidence of colorectal polyps did not differ significantly between the type 2 DM-metformin and non-type 2 DM groups(P>0.05).Furthermore,the correlations between the duration of metformin use and the incidence of colorectal polyps and between the size and number of polyps and metformin use were not statistically significant(P>0.05).Metformin use did not affect the incidence of colorectal polyps during interval colonoscopy(P>0.05).CONCLUSION Metformin use and colorectal polyp incidence in type 2 DM patients showed a negative correlation,independent of the hypoglycemic effect of metformin.

Polyhexamethylene biguanide chemically modified cotton with desirable hemostatic,inflammation-reducing,intrinsic antibacterial property for infected wound healing

Medical cotton dressing is cheap and widely used in diversified fields,but in the application of promoting wound healing,the continuous research of multifunctional medical cotton dressing is still of great significance.Here,we developed a fresh type of antibacterial cotton dressing through a succinct strategy based on chemically anchoring polyhexamethylene biguanide(PHMB).Intriguingly,after PHMB modification,the cotton dressing exhibited outstanding antibacterial performance which could maintain>99.99%antibacterial rate after several treatments,including washing 50 times,repeated use 10 times,UV irradiation for 7 days,cationic dyes dying,and conditioned under 90℃water bath for 2 h.In addition,the water contact angle of cotton dressing increased dramatically from 0°to 111°,which could facilitate bacterial adhesion,thus further enhance the antibacterial efficiency,and easily remove the bacterial debris.Apart from that,the developed cotton dressing showed good cytocompatibility,promoted blood clotting and expression of platelets,and promoted the wound healing process in the infection intervened skin wound model.Taken together,this antibacterial cotton dressing with desirable blood clotting,sustained protection against bacterial infection and bacterial removal features shows the potential to be a candidate for infected skin wound healing.