Objective Noninvasive Measurement of the Volumizing Effect of a Dermal Filler: An In Vivo Study.

BACKGROUND: Information about the volumizing effects of dermal fillers is critical for physicians' understanding of product features and prudent decision-making in clinical practice. It is important for material engineers to develop and optimize new dermal fillers, especially when comparing the physiochemical properties of a new product with those of existing fillers that are used worldwide. OBJECTIVE: This study aimed to establish a reliable, noninvasive method for in vivo quantitative evaluation of the filling effect in order to predict possible effectiveness after filler injection and to evaluate the degradation trend over time. METHODS: A rabbit model of ear injection with dermal fillers was established. Hyaluronic acid (HA) filler was injected into the subcutaneous layer of rabbit ears, resulting in a stable skin bulge. Ultrasonography was used to noninvasively measure the skin bulge for volume calculation; the volume change was analyzed periodically until 38 weeks. Pathological examination, the gold standard, was performed to confirm degradation. RESULTS: The immediate volumizing effect of HA filler injection was macroscopically observed as a local skin bulge. Ultrasound was able to precisely detect the shape of the filler and calculate the length, width, and height of the skin bulge at each time point. The degree of uplift and amount of residual samples in the pathological evaluation were consistent with the results of morphological observation using ultrasound. CONCLUSION: Evaluation of the volume impact of dermal filler through the rabbit ear injection model evaluation enables material science evaluation in the early stage of material development, and has certain clinical reference value. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Poly-p-dioxanone Thread Leads to Fat Metabolism Around the Thread in Pig Subcutaneous Back Fat.

Background: When poly-p-dioxanone (PDO) thread is implanted subcutaneously, in addition to collagen hyperplasia, it can also cause denaturation of surrounding adipocytes and reduce the thickness of the fat layer. Hitherto, no studies have thoroughly investigated the effects of PDO thread on adipose tissue. Objectives: In this study, the effect of PDO thread on adipose tissue was investigated in an animal model. Methods: In the current study, PDO thread was implanted into subcutaneous adipose tissue of the back in a miniature pig. Implantation site tissue and control site tissue were taken 12 weeks after implantation for hematoxylin and eosin (H&E) staining and transcriptome sequencing. Gene ontology functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis were performed to investigate the differential gene expression between PDO thread implantation and control site tissue. Results: An obvious decrease in the number, fusion, and denaturation of adipocytes can be seen by H&E staining. Sequencing analysis results showed that many of the genes identified, which were downregulated after PDO thread implantation, were involved in functions and pathways related to lipid metabolism, such as fatty acid metabolism, fatty acid degradation, and lipid cell lipolysis regulation. Some genes related to fatty acid metabolism were significantly downregulated in the PDO tissue at 12 weeks compared to the control tissue. Conclusions: Our results showed PDO thread implantation can cause a decrease in the number of adipocytes, as well as a significant alteration of the expression levels of some genes involved in lipid metabolism-related pathways. PDO thread might play an important role in promoting lipolysis.

Histopathologic analysis of hyaluronic acid composite solution following intravascular injection: Variability and safety.

BACKGROUND: Although a composite solution of non-crosslinked hyaluronic acid is generally considered safe, few studies have investigated its safety after intravascular injection. METHODS: Male Sprague-Dawley rats were administered 0.05 mL of a non-crosslinked hyaluronic acid composite solution via intravascular injection into bilateral inferior epigastric arteries (IEA). Artery samples were obtained at multiple time points for histopathologic analysis. Bilateral abdominal flaps supplied by the IEA were lifted and the same dose of solution was injected into the artery, and flap survival was analyzed. RESULTS: Histopathologic analysis showed that the non-crosslinked hyaluronic acid composite solution remained temporarily in the artery lumen following intravascular injection. With continuous blood flow, the filler gradually disintegrated and the artery became recanalized. At 24 h, no filler remained in the lumen. At 7 days after the filler was injected into the IEA feeding the flap, there was no significant difference between the experimental and control groups with respect to flap survival rate. CONCLUSIONS: Non-crosslinked hyaluronic acid composite solution is relatively safe when a minimal volume is administered by intravascular injection. The filler will remain in the vessel for a short time, after which the vessel recanalizes.

Clinical Efficacy and Safety of Non-Cross-Linked Hyaluronic Acid Combined with L-carnosine for Horizontal Neck Wrinkles Treatment.

Background Horizontal neck wrinkle formation is gaining more attention among cosmetic practitioners and clients. To date, hyaluronic acid products are one of the most common treatment options for this aesthetic concern. However, different therapeutic strategies should be given to solve the problem due to multiple etiological reasons. Given that oxidative damage plays a critical role in neck wrinkle formation, anti-oxidative compounds are now considered by physicians when making a treatment plan. Aims To evaluate the efficacy and safety of a non-cross-linked hyaluronic acid filler in combination with L-carnosine in treating horizontal neck wrinkles. Methods Thirteen patients with a Wrinkle Assessment Scale (WAS) of 2-5 for horizontal neck wrinkles were treated with L-carnosine-containing non-cross-linked hyaluronic acid. Participants were followed-up for 3 months after treatment. The post-treated WAS scores evaluated by physicians were collected when patient satisfaction was surveyed. Any post-treatment adverse events were recorded. Results With a single injection of the above filler, the physician-evaluated WAS scores improved by at least one score at one month and the improvement kept consistent as far as three months after injection. According to the last follow-up visit, 11/13 patients were satisfied with the treatment effect of their neck wrinkle. Moreover, adverse events were rare after filler injection, except for local complications that were considered common reactions to the filler injection procedure. Conclusion The non-cross-linked hyaluronic acid filler containing L-carnosine is safe and effective for treating horizontal neck wrinkles.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[Comparative Analysis of Content of Four Alkaloids in Fritillaria hupehensis and Fritillaria ebeiensis var. purpurea].

OBJECTIVE: To establish an assay method for simultaneous determination of peimine, peiminine, peimissine and hupehenine and to make a comparative analysis of the content of four alkaloids in Fritillaria hupehensis and Fritillaria ebeiensis var. purpurea for the first time. METHODS: A Unitary C18 column(250 mm x 4.6 mm, 5 µm) was chosen with acetonitrile-water (containing 0.05% diethylamine) as mobile phase in a gradient program. The column temperature was 35 degrees C and the flow-rate was 1.0 mL/min. RESULTS: There was high content of peiminine and the content of peimissine was inferior to peiminine in Fritillaria hupehensis. Relatively speaking, peimine and hupehenine were much lower than the other two ingredients. Fritillaria ebeiensis var. purpurea also contained high levels of peiminine, the minimum content of peimine and equivalent content of peimissine comparing with Fritillaria hupehensis. In addition, it didn't contain hupehenine in Fritillaria ebeiensis var. purpurea. CONCLUSION: This method is simple and fast, and it has good separation, reproducibility and reliable results. Also, it can be used as basis for the quality evaluation of Fritillaria hupehensis and Fritillaria ebeiensis var. purpurea.