Abstract:

Objective To investigate the efficacy of autologous platelet-rich gel （APG） prepared by different methods on diabetic foot wound healing and antibacterial activity in vitro. Methods In the wound healing trial， 80 patients with diabetic foot ulcers admitted to The Third People's Hospital of Yunnan Province from 2024 to 2025 were randomly divided into four groups （n=20 each）： Single centrifugation APG group， double centrifugation APG group， machine-harvested APG group， and debridement gel control group. fasting blood glucose （FBG）， erythrocyte sedimentation rate （ESR）， interleukin-6 （IL-6）， procalcitonin （PCT）， C-reactive protein （CRP）， antithrombin Ⅲ（AT-III）， tumor necrosis factor-α （TNF-α）， homocysteine （Hcy）， and ulcer area reduction rate were compared before and after treatment. In the in vitro antibacterial test， 20 diabetic patients were additionally enrolled. Three types of APG were used as experimental groups， with platelet-poor plasma （PPP） group and saline solution as controls. Antibacterial effects against Staphylococcus aureus， Escherichia coli， extended-spectrum β-lactamase-producing Escherichia coli， and Pseudomonas aeruginosa were observed. Results After treatment， significant differences were found in laboratory parameters among the four groups （P < 0.05）. Pairwise comparisons showed that AT-Ⅲ was higher in the three experimental groups than in the control group， while the other seven indicators were lower （P < 0.05）. After the first and third dressings， significant differences were observed in ulcer area， ulcer area reduction rate， and final efficacy among the four groups （P < 0.05）； the control group was inferior to the experimental groups. The ulcer area reduction rate was significantly lower in the control group than in the three experimental groups at each time point （P < 0.001）， with no significant difference among experimental groups （P > 0.05）. The ulcer area reduction rate increased significantly over time （P < 0.001）， with different temporal patterns between groups； the control group had lower healing rates than experimental groups at all time points. Treatment group， baseline ulcer area， and the aforementioned laboratory parameters were significantly different among groups （P < 0.05）. For more severe Wagner grade 3 ulcers， APG treatment provided definite clinical improvement superior to conventional therapy. Multivariate logistic regression showed that all three experimental groups were strong predictors of marked efficacy （P < 0.05）， whereas baseline ulcer area， fasting blood glucose， and other indicators had no significant effect （all P > 0.05）. All three experimental groups exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus at 4 ? 12 hours， with similar levels among groups. None of the five groups showed antibacterial activity against extended-spectrum β-lactamase-producing Escherichia coli or Pseudomonas aeruginosa； the PPP group and control group had no effect on any strain. Antibacterial activity decreased over time and was almost absent at 24 hours. Conclusions APG prepared by the three methods effectively reduces blood glucose， improves clinical parameters， and promotes wound healing in diabetic foot patients. Autologous platelet-rich gel displays a specific antibacterial spectrum， and its antibacterial effect against different bacterial genera is time-dependent.

Key words: platelet-rich gel, preparation method, diabetic foot ulcer, wound healing, inflammatory factor, in vitro bacteriostasis