Background: The role of autophagy in the formation of hypertrophic scars (HS) remains unclear. This study aimed to explore the role and potential mechanism of autophagy during the development of HS. Methods: RNA and protein expression levels of Beclin-1, p62, and LC3II in normal skin tissues and HS specimens from different patients were examined. Autophagy inducers and inhibitors were used to cure established HS in rabbit ears, and the expression of Beclin-1, p62, and LC3II at the RNA and protein level was determined. Lastly, the effects of autophagy inducers and inhibitors on HS development were analyzed. Results: Compared to normal skin tissues, the expression of LC3Ⅱ and Beclin-1 was higher (P<0.05), while that of p62 was lower (P<0.05) in HS tissues. In addition, the LC3II/LC3I ratio was increased during HS formation, and the altered expression of the three proteins stabilized after one year. Administration of autophagy inducers enhanced the formation of HS as well as the expression levels of LC3II and Beclin-1 but decreased p62 expression. Meanwhile, administration of autophagy inhibitors increased the expression of LC3II, Beclin-1, and p62, along with reduced HS formation. Conclusion: Autophagic activity increased during HS initiation and subsequent stabilization. In addition, autophagy inhibitors were able to inhibit HS formation by suppressing autophagy, whereas autophagy inducers promoted scar hyperplasia by enhancing autophagy.

The prevention and treatment of scars has always been an important task in the field of wound repair.Humans have started treatment for scars long time ago and have created a series of treatments.At the same time,with the development of science and technology,the diagnosis and treatment of scars have made great progress.Through the basic research for new therapeutic targets and innovative of treatment methods,treatment for scar turns more diversified and integrated.As a result,clinicians will suffer many challenges while having more options for scars treatment.Combined with traditional treatment,developing new treatments,and the comprehensive therapy of multiple treatment methods is the mainstream trend of scar treatment.

Objective To explore the differences in autophagic expression levels between hypertrophic scar (HS) tissue and normal skin tissue,and further investigate the relationship between hypertrophic scar formation and autophagy protein expression through the rabbit ear hypertrophic scar model.Methods 30 patients with hypertrophic scar were collected.One hypertrophic scar tissue and one normal skin tissue were harvested.The relative expressions of LC3,P62 and Beclin-1 in each tissue specimen were detected by immunohistochemistry and Western blot.Western blot was used to detect the autophagic-associated protein LC3 (MAPLC3),P62 and Beclin-1 in the hypertrophic scar tissue of rabbit ear and the corresponding normal tissue of rabbit ears at 4 weeks,8 weeks,12 weeks,and 24 weeks,and further explore their clinical significance.Results In vivo,the expression of hypertrophic scar tissue protein LC3 and Beclin-1 was significantly stronger than that in normal skin tissue (P ＜ 0.05).The expression of P62 was significantly weaker than that in normal skin tissue (P ＜ 0.05).In animal experiments,during the process of HS formation,the protein expression of LC3 gradually increased,while the protein expression of P62 gradually decreased;the protein expression of Beclin-1 was higher than that of normal rabbit ears tissue,with statistically significant differences (P ＜ 0.05).Conclusions The expression of LC3 and Beclin-1 in human hypertrophic scar tissues is higher than that in normal tissues.While the expression of P62 is lower than that in normal tissues.That is,the expression of autophagy in human hypertrophic scar tissue showed an upward trend in a certain period of time,and was significantly higher than that in normal tissue.

To reconstruct the auricle using a porous, hollow, three‐dimensional (3D)‐printed mold and autologous diced cartilage mixed with platelet‐rich plasma (PRP).

Objective To investigate the expression and the relationship with angiogenesis of miR-195 and NLR family member X1 (NLRX1) in granulation tissue after negative-pressure wound treatment (NPWT).Methods Six patients were collected who received negative pressure treatment with refractory wound granulation.The levels of miR-195, NLRX1 mRNA and NLRX1 proteins were measured.The expression of NLRX1 and the micro-vascular density (MVD) of CD31 were detected by immunohistochemistry (IHC).Results MiR-195 and MVD were significantly higher in granulation tissue after 7 days negative pressure treatment (P＜0.05), and NLRX1 was significantly lower (P ＜0.05).In granulation tissue,the expression of miR-195 was negatively correlated with NLRX1 (r =-0.856, P ＜0.001), the expression of NLRX1 was negatively correlated with MVD (r =-0.618, P ＜0.05), and the expression of miR-195 was positively correlated with MVD (r =0.630, P ＜ 0.05).Conclusions Negative pressure wound therapy can promote the formation of granulation vessels and the wound healing.The therapeutic mechanism may inhibit the expression of NLRX1 and upregulate the expression of miR-195 to promote angiogenesis.

Wound dressings with drug delivery system have drawn increasing attention in skin damage recombination. Herein, a novel composite biological dressing was prepared and based on poly(vinyl alcohol) (PVA) combined with carbon nanotubes (CNTs) and epidermal growth factor (EGF) by electrospinning on gauze. The properties of the CNTs/PVA/EGF composite dressing were systemically investigated by general observation, and scanning electron microscopy (SEM). In vitro, the cytotoxicity of this dressing was investigated using a methyl thiazolyl tetrazolium (MTT) assay on L929 fibroblasts. In order to study the sustained release of EGF from this dressing, the concentration of EGF at different times was tested by ELISA. Furthermore, the biological activity of the released EGF was also evaluated using the MTT assay. Moreover, an in vivo experiment was conducted to observe whether this dressing was capable of improving healing in the model of wounded skin on rats. It was revealed that this dressing had a well-distributed microstructure by SEM. Additionally, the grade of cytotoxicity was low, and the EGF had a sustained release rate from this dressing. Furthermore, a maximum accumulative release rate of 12.47% was identified at 12 h, and was retained at 9.4% after 48 h. Simultaneously, the relative growth rate of L929 fibroblasts in the 12 h experimental group and 48 h group was 291.24 and 211.3%, respectively. Next, the efficacy of these products was evaluated in vivo using Sprague-Dawley rats with a skin injury model. The healing of wounded skin of rats was sped up by this dressing based on the gross and histological appearances. From 7 to 10 days, the wounds in the experimental group were almost healed. In conclusion, this CNTs/PVA/EGF dressing had a well-distributed structure and an ability to release EGF at a sustained rate with the activity being favorable. On the basis of those results, a positive influence of designed dressing for accelerated wound healing was confirmed.

Objective: To assess the viability and biomechanics of bare diced cartilage grafts. Methods: Cartilage samples were collected from 1 ear in 15 rabbits as well as costal cartilage. Each rabbit was inserted bare diced- and single-strip costal-cartilage grafts, respectively, into paraspinal subcutaneous pockets: after euthanasia at 2 months, specimens were weighed, with diced cartilage grafts examined histomorphologically by hematoxylin-eosin staining, masson trichrome staining, and immunohistochemistry. Finally, biomechanical properties of grafts were assessed. Results: Bare diced cartilage grafts were connected into an integrated mass after 2 months, and inward growth of fibrous tissues and angiogenesis were observed. Mean wet weights of diced cartilage grafts were 1.603 ± 0.278 and 1.662 ± 0.204 g pre- and postoperation, respectively; those of costal cartilage grafts were 0.053 ± 0.008 and 0.058 ± 0.008 g, respectively. In compression assays, mean modulus values of elasticity at yield in diced- and costal-cartilage grafts were 7.65 ± 0.59 and 22.30 ± 1.15 MPa, respectively (P < 0.05); mean stress values were 4.07 ± 0.38 and 12.50 ± 1.15 MPa, respectively (P < 0.05). In the tensile test, mean modulus values of elasticity at yield of diced- and costal-cartilage grafts were 4.70 ± 0.78 and 10.59 ± 1.39 MPa, respectively (P < 0.05), mean stress values were 0.82 ± 0.05 and 1.76 ± 0.21 MPa, respectively (P < 0.05). Conclusions: Diced cartilage grafts had favorable viability and growth. Despite reduced elasticity and stress values, they still can be served as substitute for supportive filling materials.

Objectives: The objective of this study was to investigate the viability and biomechanics of diced cartilage blended with platelet- rich plasma (PRP) and wrapped with poly (lactic-co-glycolic) acid (PLGA) membrane in a rabbit model.Methods: A total of 10 New Zealand rabbits were used for the study. Cartilage grafts were harvested from 1 side ear. The grafts were divided into 3 groups for comparison: bare diced cartilage, diced cartilage wrapped with PLGA membrane, and diced cartilage blended with PRP and wrapped with PLGA membrane. Plateletrich plasma was prepared using 8mL of auricular blood. Three subcutaneous pockets were made in the backs of the rabbits, and the grafts were placed in these pockets. The subcutaneous implant tests were conducted for safety assessment of the PLGA membrane in vivo. All of the rabbits were sacrificed at the end of 3 months, and the specimens were collected. The sections were stained with hematoxylin and eosin, toluidin blue, and collagen II immunohistochemical. Simultaneously, biomechanical properties of grafts were assessed.Results: This sample of PLGA membrane was conformed to the current standard of biological evaluation of medical devices. Moderate resorption was seen at the end of 3 months in the gross assessment in diced cartilage wrapped with PLGA membrane, while diced cartilage blended with PRP had no apparent resorption macroscopically and favorable viability in vivo after 3 months, and the histological parameters supported this. Stress-strain curves for the compression test indicated that the modulus of elasticity of bare diced cartilage was 7.65 +/- 0.59 MPa; diced cartilage wrapped with PLGA membrane was 5.98 +/- 0.45 MPa; and diced cartilage blended with PRP and wrapped with PLGA membrane was 7.48 +/- 0.55 MPa, respectively.Conclusions: Diced cartilage wrapped with PLGA membrane had moderate resorption macroscopically after 3 months. However, blending with PRP has beneficial effects in improving the viability of diced cartilages. Additionally, the compression modulus of diced cartilage blended with PRP and wrapped with PLGA membrane was similar to bare diced cartilage.