Ultrasound-assisted isolation:A new method to isolate stromal vascular fraction

Background:The stromal vascular fraction(SVF),a cluster of stem and progenitor cells isolated from adipose tissue,holds significant promise for application in regenerative medicine.However,the existing methods for SVF isolation are time-consuming and expensive.Thus,in this study,we explored a new method of SVF extrac-tion-ultrasound-assisted SVF isolation(USASI)-and compared the viability and characteristics of SVF isolated using different methods.Methods:SVF extraction methods using different combinations of ultrasound power,ultrasound time,collagenase dosage,and collagenase digestion time were compared with those of the control group(collagenase digestion method).The cell yield and vitality of the SVF were evaluated via cell counting and trypan blue staining.The cell components and immunophenotypes of freshly isolated SVF were analyzed using flow cytometry.The prolifer-ative capacity and differentiation potential of the SVF were also identified.Results:Ultrasonication at 95 W-20 kHz for 30 s followed by digestion with 0.15%collagenase for 30 min was identified as the most suitable parameter for the USASI method in isolating SVF,as recommended based on the evaluation of various tested conditions.The USASI method significantly reduced the collagenase dosage and shortened the digestion time.Compared to the collagenase digestion method,the USASI method had a higher cell yield and cell viability,with no adverse effects on cell components,proliferative capacity,or multipotential differentiation capacity.Conclusion:With reduced processing time,lower collagenase dosage,and increased cell yield without impairing the viability and characteristics of SVF,USASI holds the potential to emerge as a time-saving and cost-effective method for future clinical applications.

Enhancing tissue regeneration studies with luciferase-transgenic rats and bioluminescence imaging:A comprehensive review

Bioluminescence imaging(BLI)in rodent models has revolutionized preclinical research in recent decades,enabling precise and noninvasive observation of cellular and molecular processes in vivo.Among various bioluminescent systems,the firefly luciferase-luciferin system is one of the most widely employed for in vivo cell tracking.This comprehensive review focuses on using luciferase-transgenic(Luc-Tg)rat models,known as firefly rats,in conjunction with BLI to investigate tissue regeneration and stem cell dynamics.Compared with other imaging modalities,BLI offers enhanced tissue penetration,reduced background noise,and the capacity to perform longitudinal studies with fewer animals,aligning with ethical research principles.Applications of Luc-Tg rats in fat grafting,soft tissue expansion,hair growth cycle analysis,and other skin studies are discussed,demonstrating the versatility and precision of BLI in tracking complex biological processes.Integrating advanced analytical and genome-editing techniques with BLI promises to enhance data interpretation’s accuracy and efficiency.These advancements have deepened our understanding of the cellular fate and mechanisms underlying tissue regeneration,presenting promising avenues for optimizing therapeutic strategies in reconstructive surgery and regenerative medicine.Combining luciferase reporter genes and BLI is crucial to unraveling complex biological phenomena,advancing soft tissue regeneration research,and developing innovative therapeutic strategies for various medical conditions.

A randomized clinical trial assessing the efficacy of single and multiple intralesional collagenase injections for treating contracted scars

Background:Scar contractions caused by trauma or burns can cause secondary physical dysfunction and disfigurement.Many minimally invasive methods for scar contraction have shown limited applicability and efficacy.This study investigated the feasibility and efficacy of intralesional collagenase injections for scar contraction treatment.Methods:Patients with contracted scars who had limited joint movement and physical disfiguration for>1 year were enrolled in this single-blind,randomized clinical trial from July 2017 to February 2018 at Shanghai Ninth People’s Hospital.Collagenase was injected into the firm-contracted scar(15 U/cm^(2))three times at 4-week intervals in the multiple treatment group and once in the single treatment group,and a placebo injection was performed in the control group.Scar length and skin texture were documented at the 4-and 12-week follow-ups.The safety of the collagenase treatment was also evaluated.Results:The contracted scar was significantly elongated after both single and multiple collagenase treatments.The results showed that,compared to a one-time treatment,repeated injections were more effective at 12 weeks,with an average improvement of 26.83(15.79%).At 12 weeks,78.9% of the patients in the multiple group and 52.9%in the single group achieved significant improvement at 12 weeks.No severe adverse events were observed.Conclusion:Intralesional collagenase injection showed promising results in improving scar contraction and provides an alternative treatment for patients.

Concentrated Growth Factor from Autologous Platelet Promotes Hair Growth in Androgenetic Alopecia

Studies have shown that platelet concentrates can induce the proliferation of the dermal papilla and the vascularization of the perifollicular tissue, as well as accelerate the telogen-to-anagen transition, thereby promoting the regrowth of hair improving the appearance of hair loss. Herein, we report on the application of a new, modified form of platelet concentrates, namely, concentrated growth factors (CGFs), in 15 cases of androgenetic alopecia (AGA). 15 cases of androgenetic alopecia were treated with the use of monthly, subcutaneous injections of autologous CGF in the scalp. A total of 3 injections were administered 4 weeks apart, and the patients were followed up for 6 months. Assessments were performed before the treatments and at 4, 8, 12 and 24 weeks after the first treatment. The treatment outcomes were assessed by taking macroscopic photographs and trichoscopic photomicrographs, as well as by using the Global Aesthetic Improvement Scale (GAIS) and the patient satisfaction survey. In order to determine the safety of the treatment, the injection area was observed for signs of infection or mass evaluation. The photographs showed significant improvement in hair appearance after injections of CGF. The hair photomicrographs showed that CGF promoted the regrowth of hair in balding areas, with an increased hair density and an increased ratio of terminal to vellus hair. The GAIS suggested that CGF treatments were effective in treating AGA, and the majority of patients were satisfied with their improvement. In addition, treatments resulted in a faster rate of hair growth and a decrease in the greasy and unpleasant sensation of the hair of the patients. At the last visit, none of the 15 patients reported experiencing side-effects during the follow-up period. To conclude, the application of CGF can be an effective method in the treatment of androgenetic alopecia.