Regional differences in cell-mediated immunity in people with diabetic peripheral neuropathy

Atelocollagen-based hydrogel loaded withCotinus coggygriaextract for treatment of type 2 diabetic wounds

Diabetes, a chronic metabolic disease, causes complications such as chronic wounds, which are difficult to cure. New treatments have been investigated to accelerate wound healing. In this study, a novel wound dressing from fibroblast-laden atelocollagen-based hydrogel withCotinus coggygriaextract was developed for diabetic wound healing. The antimicrobial activity ofC. coggygriahexane (H), dichloromethane (DCM), dichloromethane:methanol (DCM-M), methanol (M), distilled water (DW) and traditional (T) extracts againstStaphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalisandCandida albicans, as well as their cytotoxic effects on fibroblasts were determined. While fibroblast growth was significantly (p< 0.05) promoted with DCM (121.41 ± 1.04%), M (109.40 ± 5.89%) and DW (121.83 ± 6.37%) extracts at their lowest concentrations, 2000 μg ml-1DCM and 7.8 μg ml-1T extracts had both non-cytotoxic and antifungal effects. An atelocollagen-based hydrogel was produced by thermal crosslinking, and its pore size (38.75 ± 7.67 μm), water content (96.63 ± 0.24%) and swelling ratio (27.21 ± 4.08%) were found to be suitable for wound dressings. A significant increase in the deoxyribonucleic acid amount (28.27 ± 1.41%) was observed in the plain hydrogel loaded with fibroblasts after 9 d of incubation, and the hydrogel had an extensively interconnected cellular network. The hydrogels containing DW and T extracts were applied to wounds generated in anin vitro3D type-2-diabetic human skin model. Although the incubation period was not sufficient for closure of the wounds in either of the treatments, the hydrogel with T extract stimulated more fibroblast migration. In the fibroblast-laden version of the hydrogel with T extract, no wound closure was observed but more keratinocytes migrated to the wound region. These positive outcomes underline the potential of the developed wound dressing as a powerful alternative to improve diabetic wound healing in clinical practice.

Regional differences in cell-mediated immunity in people with diabetic peripheral neuropathy

AIM

To study cell-mediated immunity in the feet of people with type 2 diabetes with polyneuropathy.

METHODS

In a cohort comprising people with type 2 diabetes with polyneuropathy (n = 17) and without polyneuropathy (n = 12) and a healthy control group (n = 12) indurations due to delayed-type hypersensitivity responses to intracutaneous Candida albicans antigen were determined in the foot and compared with those in the arm (an area relatively spared in diabetic polyneuropathy). The sizes of indurations on the foot were correlated with electromyographic measurements in the participants with diabetes.

RESULTS

No differences were observed in the median size of indurations between the foot and arm in healthy controls and participants without polyneuropathy; in participants with polyneuropathy, induration sizes on the foot were smaller than on the arm: 0 (95% CI 0 to 1) vs 5 (95% CI 2 to 6) mm (P < 0.01). In participants with diabetes, larger indurations correlated with better nerve function (Spearman's rho 0.35 to 0.39).

CONCLUSION

Our findings suggest that diabetic peripheral polyneuropathy negatively affects cell-mediated immunity in the foot. (Clinical Trials registry no.: NCT01370837).