Therapeutic role of exosomes and conditioned medium in keloid and hypertrophic scar and possible mechanisms.

Exosomes, ranging from 40 to 160 nm in diameter, are extracellular lipid bilayer microvesicles that regulate the body's physiological and pathological processes and are secreted by cells that contain proteins, nucleic acids, amino acids and other metabolites. Previous studies suggested that mesenchymal stem cell (MSC)-derived exosomes could either suppress or support keloid and hypertrophic scar progression. Although previous research has identified the potential value of MSC-exosomes in keloid and hypertrophic scar, a comprehensive analysis of different sources of MSC-exosome in keloid and hypertrophic scar is still lacking. This review mainly discusses different insights regarding the roles of MSC-exosomes in keloid and hypertrophic scar treatment and summarizes possible underlying mechanisms.

Comparative study of treatment for striae alba stage striae gravidarum: 1565-nm non-ablative fractional laser versus fractional microneedle radiofrequency.

Striae gravidarum is a common dermatologic condition for females caused by multiple factors during pregnancy. It remains a therapeutic challenge especially in the striae alba (SA) stage, generating psychological and emotional distress to those affected. This study aims to compare the efficacy and safety of 1565-nm non-ablative fractional laser (NAFL) and fractional microneedle radiofrequency (MRF) for treatment of SA striae gravidarum. Fourteen Chinese women with SA striae gravidarum were included in this study. Patient abdomens were randomly divided into NAFL and MRF treatment sides, treated three times at 6-week intervals. Treatment efficacy was evaluated by subjective (clinical assessments, patient satisfaction rating, adverse effects assessment) assessments and objective (skin melanin index measurement, histological study) assessments. Clinical assessment suggested MRF was more effective (P = 0.0143) for improving the appearance of SA striae gravidarum. Both NAFL and MRF demonstrated effective improvement (P = 0.0082 and P = 0.0158, respectively), with no significant difference according to patient satisfaction ratings and changes in melanin index (P = 0.5900). Both treatments induced limited adverse reactions, but MRF treatment caused significant pain compared with the more moderate NAFL treatment (P = 0.0003). MRF treatment increased neocollagen and elastic fibers more significantly than NAFL, based on histological assessments (P = 0.0298 and P = 0.0048, respectively). MRF treatment improved collagen regeneration in SA striae gravidarum more than NAFL but caused considerable pain during treatment. Corresponding treatment or therapeutic strategies should be applied according to clinical scenario.

Successful treatment of facial hypertrophic scar with HMME-PDT: A case report.

Treating hypertrophic scars is a challenge for clinicians. Herein, we report a case of one female with both a facial port wine stain and a hypertrophic scar treated with Hematoporphyrin monomethyl ether photodynamic therapy. Surprisingly, with the treatment of the facial port wine stain, the other skin lesion, the hypertrophic scar, also alleviated. HMME-PDT has been approved for application in PWS; however, this case showed effective easing of the hypertrophic scar lesion, which indicates that it might be a promising therapeutic method for hypertrophic scars.

Susceptibility of epithelial tumour cell lines to hyperthermia.

BACKGROUND: Human skin or mucosa exposes cells to both an internal and exogeneous thermal environment and the cells survive within a certain range of temperature. Exogeneous hyperthermia has been applied for the treatment of various types of cancers, fungal disease, and warts. OBJECTIVES: To determine whether different cellular components in the skin adapt to hyperthermic conditions differentially and further elucidate the mechanisms involved. MATERIALS & METHODS: Cell lines derived from normal and tumour epithelial cells were treated with hyperthermic conditions and tested for viability (using an MTS assay), apoptosis (using a FITC-conjugated annexin V apoptosis detection kit), and changes in intracellular calcium (using a calcium-sensitive fluorescent single-wavelength dye, Fluo-4 AM). RESULTS: Thermo-resistance of different cell types was different when cells were subjected to heat at 45̊C for 30 minutes. Stronger effects of hyperthermia were noted on cell viability and apoptosis in epidermal cells relative to their malignant counterparts, except for cell lines harbouring human papillomavirus (HPV). Hyperthermia had a much greater effect on cell viability and apoptosis in a HPV-negative cell line compared to HPV-positive cell lines. We further found that hyperthermia treatment resulted in a strong calcium influx which led to apoptotic cells. However, no obvious increase in apoptosis was observed in cells treated with the CRAC channel selective inhibitor, BTP2, before application of hyperthermia in all cell types, except three cervical cell lines harbouring HPV. CONCLUSION: We propose that hyperthermia results in a CRAC-related strong calcium influx which induces apoptosis, with the exception of HPV-positive cells.

Clinical effect of ablative fractional laser-assisted topical anesthesia on human skin: A randomized pilot study.

BACKGROUND AND OBJECTIVES: Most topical medications need a long time to penetrate into the skin owing to the stratum corneum (SC) barrier. The fractional erbium-doped yttrium aluminum garnet (Er:YAG) laser has the ability to disrupt the SC and assist in the delivery of topical drugs to penetrate into the skin. This study was intended to determine whether pretreatment with a painless fractional Er:YAG laser could assist transdermal delivery of topical anesthesia. MATERIALS AND METHODS: In 22 healthy female subjects, three 4 × 3 cm regions on the right forearm were randomized to: fractional laser plus topical lidocaine cream (Group LaserAnes), sham irradiation plus topical anesthesia (Group Anes), and sham irradiation plus sham anesthesia (Group Con). After 5 minutes, each site was treated with yttrium scandium gallium garnet laser to evaluate the pain sensation using the visual analog scale. RESULTS: The average pain scores of Group LaserAnes, Group Anes, and Group Con are 3.74 ± 1.93, 4.90 ± 2.09, and 5.19 ± 2.15, respectively. The pain score of Group LaserAnes has a 25.57% reduction compared to Group Anes (p < 0.001) and a 28.70% reduction compared to Group Con (p < 0.001). There is no significant pain reduction for Group Anes compared with Group Con (p = 0.094). CONCLUSIONS: Pretreatment using fractional Er:YAG laser before topicals might be an effective method for drug delivery.