Effects of nanozeolite/starch thermoplastic hydrogels on wound healing.

BACKGROUND: Wound healing is a complex biological process. Some injuries lead to chronic nonhealing ulcers, and healing process is a challenge to both the patient and the medical team. We still look forward an appropriate wound dressing. MATERIALS AND METHODS: In this study, starch-based nanocomposite hydrogel scaffolds reinforced by zeolite nanoparticles (nZ) were prepared for wound dressing. In addition, a herbal drug (chamomile extract) was added into the matrix to accelerate healing process. To estimate the cytocompatibility of hydrogel dressings, fibroblast mouse cells (L929) were cultured on scaffolds. Then, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium-bromide assay test and interaction of cells and scaffolds were evaluated. For evaluating healing process, 48 male rats were randomly divided into four groups of four animals each (16 rats at each step). The ulcers of the first group were treated with the same size of pure hydrogels. The second group received a bandage with the same size of hydrogel/extract/4 wt% nZ (hydrogel NZE). The third group was treated with chamomile extract, and the fourth group was considered as control without taking any medicament. Finally, the dressings were applied on the chronic refractory ulcers of five patients. RESULTS: After successful surface morphology and cytocompatibility tests, the animal study was carried out. There was a significant difference between starch/extract/4 wt% nZ and other groups on wound size decrement after day 7 (P < 0.05). At the clinical pilot study step, the refractory ulcers of all five patients were healed without any hypersensitivity reaction. CONCLUSION: Starch-based hydrogel/zeolite dressings may be safe and effective for chronic refractory ulcers.

A novel drug delivery system using acyclovir nanofiber patch for topical treatment of recurrent herpes labialis: A randomized clinical trial.

OBJECTIVES: Topical treatment with acyclovir cream has shown low efficacy in recent studies. Nano drug delivery systems, have received much attention in recent decades. The aim of this study was to compare the efficacy of acyclovir nanofiber patch with acyclovir cream. MATERIAL AND METHODS: In this double-blind three-armed randomized clinical trial, a total of 60 patients with recurrent labial herpes, were randomly divided into three groups, each consisting of 20. The patients in the first, second, and third groups were treated with acyclovir nanofiber patch, placebo nanofiber patch, and acyclovir cream, respectively. A numerical scale was used by the patients to record the self-reported symptoms. Symptoms score, crusting time and healing time were assessed by the clinician. Kruskal-Wallis test was used to compare the symptoms between the three groups, a survival test was also performed to evaluate the crusting and healing time. Data were analyzed in SPSS V22 at P-value < 0.05. RESULTS: The mean scores of symptoms at baseline were 1.6, 1.5, and 1.4 in the first, second, and third groups, respectively. The symptoms were not significantly different between the three groups on different treatment days. The mean crusting time was 2.3, 2.4, and 2.6 days in the three groups, and the mean healing time was 7.4, 7.2, and 7.7 days, respectively. Crusting time and healing time were not significantly different between the three groups. CONCLUSIONS: Acyclovir nanofiber patches are recommended for accelerating symptom relief in recurrent labial herpes, however, they are not effective in shortening the crusting or healing time. CLINICAL TRIAL REGISTRATION NUMBER: IRCT20141124020073N2. Registered in: Iranian Registry of Clinical Trials (www.irct.ir).

Incorporation of mesoporous silica nanoparticles into random electrospun PLGA and PLGA/gelatin nanofibrous scaffolds enhances mechanical and cell proliferation properties.

Poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974±68nm for the pure PLGA scaffolds vs 832±70, 764±80, and 486±64 for the PLGA/gelatin, PLGA/10wt% MSNPs, and the PLGA/gelatin/10wt% MSNPs scaffolds, respectively. The results suggested that the incorporation of gelatin and MSNPs into PLGA-based scaffolds enhances the hydrophilicity of scaffolds due to an increase of hydrophilic functional groups on the surface of nanofibers. With porosity examination, it was concluded that the incorporation of MSNPs and gelatin decrease the porosity of scaffolds. Nanoparticles also improved the tensile mechanical properties of scaffolds. Using in vitro degradation analysis, it was shown that the addition of nanoparticles to the nanofibers matrix increases the weight loss percentage of PLGA-based samples, whereas it decreases the weight loss percentage in the PLGA/gelatin composites. Cultivation of rat pheochromocytoma cell line (PC12), as precursor cells of dopaminergic neural cells, on the scaffolds demonstrated that the introduction of MSNPs into PLGA and PLGA/gelatin matrix leads to improved cell attachment and proliferation and enhances cellular processes.

Electrospun aligned PLGA and PLGA/gelatin nanofibers embedded with silica nanoparticles for tissue engineering.

Aligned poly lactic-co-glycolic acid (PLGA) and PLGA/gelatin nanofibrous scaffolds embedded with mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. The mean diameters of nanofibers were 641±24 nm for the pure PLGA scaffolds vs 418±85 nm and 267±58 nm for the PLGA/10 wt% MSNPs and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The contact angle measurement results (102°±6.7 for the pure PLGA scaffold vs 81°±6.8 and 18°±8.7 for the PLGA/10 wt% MSNPs and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively) revealed enhanced hydrophilicity of scaffolds upon incorporation of gelatin and MSNPs. Besides, embedding the scaffolds with MSNPs resulted in improved tensile mechanical properties. Cultivation of PC12 cells on the scaffolds demonstrated that introduction of MSNPs into PLGA and PLGA/gelatin matrices leads to the improved cell attachment and proliferation as well as long cellular processes. DAPI staining results indicated that cell proliferations on the PLGA/10 wt% MSNPs and the PLGA/gelatin/10 wt% MSNPs scaffolds were strikingly (nearly 2.5 and 3 folds, respectively) higher than that on the aligned pure PLGA scaffolds. These results suggest superior properties of silica nanoparticles-incorporated PLGA/gelatin eletrospun nanofibrous scaffolds for the stem cell culture and tissue engineering applications.

Porous starch/cellulose nanofibers composite prepared by salt leaching technique for tissue engineering.

Starch/cellulose nanofibers composites with proper porosity pore size, mechanical strength, and biodegradability for cartilage tissue engineering have been reported in this study. The porous thermoplastic starch-based composites were prepared by combining film casting, salt leaching, and freeze drying methods. The diameter of 70% nanofibers was in the range of 40-90 nm. All samples had interconnected porous morphology; however an increase in pore interconnectivity was observed when the sodium chloride ratio was increased in the salt leaching. Scaffolds with the total porogen content of 70 wt% exhibited adequate mechanical properties for cartilage tissue engineering applications. The water uptake ratio of nanocomposites was remarkably enhanced by adding 10% cellulose nanofibers. The scaffolds were partially destroyed due to low in vitro degradation rate after more than 20 weeks. Cultivation of isolated rabbit chondrocytes on the fabricated scaffold proved that the incorporation of nanofibers in starch structure improves cell attachment and proliferation.