Enhanced degradation of enoxacin using ferrihydrite-catalyzed heterogeneous photo-Fenton process.

The ferrihydrite-catalyzed heterogeneous photo-Fenton reaction shows great potential for environmental remediation of fluoroquinolone (FQs) antibiotics. The degradation of enoxacin, a model of FQ antibiotics, was studied by a batch experiment and theoretical calculation. The results revealed that the degradation efficiency of enoxacin reached 89.7% at pH 3. The hydroxyl radical (∙OH) had a significant impact on the degradation process, with a cumulative concentration of 43.9 µmol L-1 at pH 3. Photogenerated holes and electrons participated in the generation of ∙OH. Eleven degradation products of enoxacin were identified, with the main degradation pathways being defluorination, quinolone ring and piperazine ring cleavage and oxidation. These findings indicate that the ferrihydrite-catalyzed photo-Fenton process is a valid way for treating water contaminated with FQ antibiotics.

A composite hydrogel with antibacterial and promoted cell proliferation dual properties for healing of infected wounds.

Wound infection remains a major challenge for health professionals, because it delays wound healing and increases the overall cost and morbidity. Therefore, the development of new biomaterials with new antibacterial properties and healing effects remains a dire clinical need. To solve this problem, we developed silver nanoparticles embedded in γ-cyclodextrin metal-organic frameworks (Ag@MOF) and platelet-rich plasma (PRP)-loaded hydrogel systems based on methacrylated silk fibroin (SFMA) and methacrylate hyaluronic acid (HAMA) as Ag+ ion and growth factor delivery vehicles for inhibiting the growth of drug-resistant bacteria and promoting wound healing. The prepared SFMA/HAMA hydrogel demonstrated good rheological properties, swelling capability, appropriate mechanical properties and controllable biodegradability. The SFMA/HAMA/Ag@MOF/PRP hydrogel showed sustained release profiles of Ag+ ions and EGF. The SFMA/HAMA/Ag@MOF hydrogel have good inherent antibacterial properties against both gram-negative bacteria and gram-positive bacteria. The prepared hydrogel showed excellent cytocompatibility and could stimulate the growth and proliferation rate of NIH-3T3 cells. In vivo experiments showed that SFMA/HAMA/Ag@MOF/PRP hydrogel treatment enhanced the healing of full-thickness wounds, reduced inflammatory cell infiltration, and promoted re-epithelialization and collagen synthesis. All results indicated that the prepared hydrogel has tremendous potential to reduce wound infections and improve wound healing.

Human fetal mesenchymal stem cells secretome promotes scarless diabetic wound healing through heat-shock protein family.

The high mortality rate of patients with diabetic foot ulcers is urging the appearance of an effective biomedical drug. Senescence is one of the major reasons of aging-induced decline in the diabetic wound. Our previous studies have demonstrated the anti-senescence effect of secretomes derived from human fetal mesenchymal stem cells (hfMSC). The present study tends to explore the potential role of hfMSC secretome (HFS) in wound healing through anti-aging. Meanwhile, we try to overcome several obstacles in the clinical application of stem cell secretome. A verticle bioreactor and microcarriers are employed to expand hfMSC and produce the HFS on a large scale. The HFS was then subjected to lyophilization (L-HFS). The PLGA (poly lactic-co-glycolic acid) particles were used to encapsulate and protect L-HFS from degradation in the streptozotocin (STZ)-induced diabetic rat model. Results showed that HFS-PLGA significantly enhanced wound healing by promoting vascularization and inhibiting inflammation in the skin wound bed. We further analyzed the contents of HFS. Isobaric tag for relative and absolute quantitation (ITRAQ) and label-free methods were used to identify peptides in the secretome. Bioinformatics analysis indicated that exosome production-related singling pathways and heat-shock protein family could be used as bio-functional markers and quality control for stem cell secretome production.

[Comparison of functional recovery of distal radius fracture by suture of pronator muscle through modified Henry approach].

OBJECTIVE: To investigate the effect of suture of pronator muscle on forearm function after modified Henry approach for distal radius fractures. METHODS: from January 2018 to December 2020, 220 patients with distal radius fractures were treated with open reduction and locking plate internal fixation through the modified Henry approach. They were divided into two groups according to different suture methods. There were 112 cases in the intraoperative suture group, including 35 males and 77 females;The age ranged from 37 to 65(48.5±7.4) years;AO classification of fracture, 46 cases of type B and 66 cases of type C;After fracture reduction and locking plate fixation, the pronator muscle was opened and sutured. There were 108 cases in the non suture group, 32 males and 76 females;The age ranged from 34 to 67(47.6±7.8) years;There were 41 cases of fracture type B and 67 cases of fracture type C;After fracture reduction and locking plate fixation, the open pronator muscle was not sutured, and it was laid on the surface of the plate in situ. The range of wrist motion (pronation, supination, palmar inclination and dorsiflexion), the score of disability of arm shoulder and hand dash and visual analog scale(VAS) were compared between the two groups at 6 weeks and 6 months after operation. RESULTS: All 220 patients were followed up for 6 to 18 (8.5±1.3) months. There was no significant difference in the range of motion and DASH score of forearm and wrist between the two groups 6 weeks after operation (P>0.05);There was significant difference in VAS score between suture group (2.6±1.2) and non suture group (5.8±2.3)(P<0.05). Six months after operation, there was no significant difference in the range of motion, DASH score and VAS score of forearm and wrist between the two groups(P>0.05). CONCLUSION: The modified Henry approach has no obvious advantages in the range of wrist movement and upper limb function, but the intraoperative suture of pronator can reduce the early postoperative pain. It is suggested that the pronator should be sutured during the operation.

A composite hydrogel with co-delivery of antimicrobial peptides and platelet-rich plasma to enhance healing of infected wounds in diabetes.

Diabetic wound healing remains a major challenge due to its vulnerability to bacterial infection, as well as the less vascularization and prolonged inflammatory phase. In this study, we developed a hydrogel system for the treatment of chronic infected wounds, which can regulate inflammatory (through the use of antimicrobial peptides) and enhance collagen deposition and angiogenesis (through the addition of platelet-rich plasma (PRP)). Based on the formation of Schiff base linkage, the ODEX/HA-AMP/PRP hydrogel was prepared by mixing oxidized dextran (ODEX), antimicrobial peptide-modified hyaluronic acid (HA-AMP) and PRP under physiological conditions, which exhibited obvious inhibition zones against three pathogenic bacterial strains (E. coli, S. aureus and P. aeruginosa) and slow release ability of antimicrobials and growth factors. Moreover, CCK-8, live/dead fluorescent staining and scratch test confirmed that ODEX/HA-AMP/PRP hydrogel could facilitate the proliferation and migration of L929 fibroblast cells. More importantly, in vivo experiments further demonstrated that the prepared hydrogels could significantly improve wound healing in a diabetic mouse infection by regulating inflammation, accelerating collagen deposition and angiogenesis. In addition, prepared hydrogel showed a significant antibacterial activity against S. aureus and P. aeruginosa, inhibited pro-inflammatory factors (TNF-α, IL-1ß and IL-6), enhanced anti-inflammatory factors (TGF-ß1) and vascular endothelial growth factor (VEGF) production. The findings of this study suggested that the composite hydrogel with AMP and PRP controlled release ability could be used as a promising candidate for chronic wound healing and infection-related wound healing.

Antibiotic-loaded chitosan-gelatin scaffolds for infected seawater immersion wound healing.

Skin damaged during sea battles is vulnerable to seawater immersion and bacterial infection. Scaffolds with effective biological function are highly desired for treatment of naval combat wound injuries. Herein, we prepared composite scaffolds of CS/GEL/GMs-CIP. The chitosan (CS) and gelatin (GEL) were cross-linked by genipin as matrix, and then gelatin microspheres loading ciprofloxacin hydrochloride (GMs-CIP) were add. From in vitro characterization results, CS/GEL/GMs-CIP had high water absorption ability, proper porosity, satisfactory fracture resistance, and flexibility. Furthermore, CS/GEL/GMs-CIP composite scaffold had excellent biocompatibility. Antibacterial experiments confirmed that CS/GEL/GMs-CIP had a significant inhibitory effect on E. coli, S. aureus and P. aeruginosa. The in vivo wound healing was evaluated using animal wound infection model of seawater immersion, and it was observed that the prepared composite scaffolds accelerated wound healing, reepithelialization, collagen deposition. Further analysis of wound tissue indicated that the expression of anti-inflammatory factor (TGF-ß1) was up-regulated, but the serum endotoxin levels and expression of pro-inflammatory factor (TNF-a, IL-6, and IL-1ß) were down-regulated. In summary, we believe that CS/GEL/GMs-CIP composite scaffold may serve as a promising multifunctional dressing for healing with open trauma wound infections and wound with seawater immersion.