Compositions of injectable poly-d,l-lactic acid and injectable poly-l-lactic acid

The Differences Between Sculptra and AestheFill Reconstitution Processes

Biostimulators have been increasingly popular for facial rejuvenation in recent years. Among them, Sculptra (based on poly-L-lactic acid (PLLA)) and AestheFill (based on poly-D,L-lactic acid (PDLLA)) are supplied as lyophilized powders in vials. Both need to be reconstituted with sterile water into homogeneous suspensions before injection. However, there are some differences in their reconstitution processes. This article compares the reconstitution processes of Sculptra and AestheFill.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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-d,l-lactic Acid (PDLLA) Application in Dermatology: A Literature Review

Poly-d,l-lactic acid (PDLLA) is a biodegradable and biocompatible polymer that has garnered significant attention in dermatology due to its unique properties and versatile applications. This literature review offers a comprehensive analysis of PDLLA's roles in various dermatological conditions and wound-healing applications. PDLLA demonstrates significant benefits in enhancing skin elasticity and firmness, reducing wrinkles, and promoting tissue regeneration and scar remodeling. Its biodegradable properties render it highly suitable for soft tissue augmentation, including facial and breast reconstruction. We discuss the critical importance of understanding PDLLA's physical and chemical characteristics to optimize its performance and safety, with a focus on how nano- and micro-particulate systems can improve delivery and stability. While potential complications, such as granuloma formation and non-inflammatory nodules, are highlighted, effective monitoring and early intervention strategies are essential. PDLLA's applications extend beyond dermatology into orthopedics and drug delivery, owing to its superior mechanical stability and biocompatibility. This review underscores the need for ongoing research to fully elucidate the mechanisms of PDLLA and to maximize its therapeutic potential across diverse medical fields.

Poly-d,l-Lactic Acid Via Transdermal Microjet Drug Delivery for Treating Rosacea in Asian Patients

BACKGROUND

Rosacea, a chronic inflammatory skin condition, is marked by enduring redness, visible blood vessels, and inflammatory eruptions in facial areas. Managing rosacea remains a persistent challenge for dermatologists, especially in cases unresponsive to conventional treatments. Injectable poly-d,l-lactic acid (PDLLA) has shown promise in treating erythema and telangiectasia associated with rosacea in addition to age-related concerns. Employing Mirajet, a laser-induced microjet system, for administering PDLLA is a novel and promising treatment for rosacea.

AIMS

We aimed to evaluate the efficacy and safety of injectable PDLLA delivered via a needle-free microjet system for managing rosacea.

METHODS

Four Korean women with persistent and refractory rosacea received five monthly sessions of PDLLA needle-free injections. Clinical assessments were conducted using the Clinician's Erythema Assessment and Patient's Self-Assessment (PSA) at baseline, 4 weeks post-treatment, and 22 weeks post-final treatment. Adverse events were monitored throughout the study period.

RESULTS

At 4 weeks post-treatment, both Clinician's Erythema Assessment and PSA scores indicated significant improvements in erythema that were sustained up to the 22-week follow-up. Patients reported high satisfaction with resolution of redness and improved skin texture. Mild swelling, redness, and petechiae were observed post-treatment but resolved spontaneously. No product-related adverse events were noted during the study period.

CONCLUSION

Injectable PDLLA delivered via laser-induced microjet injection demonstrated promising efficacy in improving rosacea symptoms and skin quality for up to 22 weeks without significant adverse effects. Larger randomized controlled trials are needed to confirm these findings and evaluate long-term safety and sustainability of outcomes.

Cross-linked Sodium Hyaluronate Gel with PLLA-b-PEG Microsphere for Facial Contouring in Chinese: A Retrospective Study

BACKGROUND

In Asia, the demand for cosmetic facial treatments has surged due to technological advancements, increased social acceptability, and affordability. Poly-L-lactic acid (PLLA) fillers, known for their biocompatibility and biodegradability, have emerged as a popular choice for facial contouring, yet studies specifically addressing their use in Asian populations are scarce.

METHODS

This retrospective study examined 30 Chinese patients who underwent facial contouring with PLLA fillers, focusing on product composition, injection techniques, and safety measures. A comprehensive clinical evaluation was performed, including the Global Aesthetic Improvement Scale (GAIS) and Global Impression of Change Scale (GICS) for effectiveness and patient satisfaction, respectively.

RESULTS

No significant difference in GAIS scores was observed between injectors and blinded evaluators over a 12-month period, indicating consistent effectiveness. Patient satisfaction remained high, with GICS scores reflecting positive outcomes. The safety profile was favorable, with no serious adverse events reported. The study highlighted the importance of anatomical knowledge to avoid complications, particularly in areas prone to blindness.

CONCLUSIONS

PLLA fillers offer a safe, effective option for facial contour correction in the Asian population, achieving high patient satisfaction and maintaining results over time. The study underscores the need for tailored approaches in cosmetic procedures for Asians, considering their unique facial structures and aesthetic goals. Further research with larger, multicenter cohorts is recommended to validate these findings and explore long-term effects.

LEVEL OF EVIDENCE III

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‐d,l‐lactic acid‐enhanced atrophic scar treatment via transdermal microjet drug delivery in Asians

BACKGROUND

Acne vulgaris often results in permanent scars, with atrophic scars being the most common type and posing a significant therapeutic challenge due to their prevalence and impact on patients' quality of life. Various treatment options exist, including the use of poly-d,l-lactic acid delivered via different methods.

OBJECTIVE

This study aimed to assess the efficacy and safety of poly-d,l-lactic acid delivered via laser-assisted needle-free microjet injection for treating atrophic scars.

METHODS

Five Korean participants with atrophic facial scars were recruited. Poly-d,l-lactic acid solution was administered via the Mirajet system in five sessions, with clinical assessments conducted at baseline, before each session, and at 12-week and 22-week follow-ups. Outcome measures included the Global Aesthetic Improvement Scale and patient satisfaction scores.

RESULTS

Positive results were observed at the 12-week and 22-week follow-ups, with high patient satisfaction and improvements in atrophic scars and skin texture. Mild discomfort and transient side effects were reported, with no adverse events observed during the follow-up period.

CONCLUSION

Poly-d,l-lactic acid delivered by a laser-assisted needle-free microjet injector was judged to be effective for improving atrophic the facial area. Further research, particularly through randomized controlled trials, is needed to validate these findings and assess the longer-term safety and sustainability of outcomes.

Consensus recommendations on the use of injectable poly-l-lactic acid in Asian patients

BACKGROUND

Injectable poly-L-lactic acid (PLLA) has been proven safe and effective with numerous medical applications for more than 25 years. The product has been approved in over 40 countries and is being used for soft tissue augmentation in the face and certain body parts. With the increased demand for subtle and natural-looking aesthetic treatments in the Asia-Pacific region, there is also a heightened need for consistent preparation and effective treatment methodologies to optimize outcomes for Asian patients.

METHODS

The body of evidence in medical literature, clinical data of presented case reports, and the collective experience of the authors are reflected in these consensus recommendations, which also take under consideration the availability of biostimulators in the Asia-Pacific region.

RESULTS

The resulting consensus recommendations include patient selection and assessment, management of treatment expectations, appropriate preparation and storage, proper injection techniques and treatment plans, management of adverse effects, PLLA combination with other facial rejuvenation procedures, and other constructive considerations.

CONCLUSIONS

In the above consensus recommendations, the authors shared their best practices in accordance with the updated preparation and treatment protocols of PLLA. These recommendations represent the clinical and real-world techniques utilized by authors in providing PLLA treatments for Asian patients.

Laser-Assisted and Device-Assisted Filler Delivery: A Histologic Evaluation

BACKGROUND

Lasers and devices are used to enhance transcutaneous delivery of fillers. However, little has been published on the histologic findings of this form of laser/device-assisted delivery to determine the optimal devices and fillers.

OBJECTIVE

To objectively evaluate the histological effects of laser-assisted and device-assisted filler delivery.

METHODS

Ex vivo human abdominoplasty skin samples were treated with fractional CO 2 laser (ECO 2 , 120 μm tip, 120 mJ), fractional radiofrequency microneedling (FRMN, Genius, 1.5 mm, 20 mJ/pin), and microneedling (2.0 mm). Immediately after poly- l -lactic acid (PLLA), hyaluronic acid gel, calcium hydroxylapatite, and black tissue marking dye were topically applied. After treatment, biopsies were collected for histologic evaluation.

RESULTS

Histology revealed that PLLA and black dye were found in greatest abundance, hyaluronic acid was found to a lesser extent, and calcium hydroxylapatite was least found within channels created by fractional CO 2 laser. Microneedling was effective only at delivering black dye, whereas FRMN failed to show significant channel formation or delivery of the studied products.

CONCLUSION

Among the devices and fillers studied, fractional CO 2 laser and PLLA proved to be the most effective combination for laser/device-assisted filler delivery. Neither microneedling nor FRMN was effective as devices to enhance filler delivery.

Poly-D,L-Lactic Acid Stimulates Angiogenesis and Collagen Synthesis in Aged Animal Skin

Angiogenesis promotes rejuvenation in multiple organs, including the skin. Heat shock protein 90 (HSP90), hypoxia-inducible factor-1 alpha (HIF-1α), and vascular endothelial growth factor (VEGF) are proangiogenic factors that stimulate the activities of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and extracellular signal-regulated kinase 1/2 (ERK1/2). Poly-D,L-lactic acid (PDLLA), polynucleotide (PN), and calcium hydroxyapatite (CaHA) are dermal fillers that stimulate the synthesis of dermal collagen. However, it is not yet known whether these compounds promote angiogenesis, which leads to skin rejuvenation. Here, we evaluated whether PDLLA, PN, and CaHA stimulate angiogenesis and skin rejuvenation using H₂O₂-treated senescent macrophages and endothelial cells as an in vitro model for skin aging, and we used young and aged C57BL/6 mice as an in vivo model. Angiogenesis was evaluated via endothelial cell migration length, proliferation, and tube formation after conditioned media (CM) from senescent macrophages was treated with PDLLA, PN, or CaHA. Western blot showed decreased expression levels of HSP90, HIF-1α, and VEGF in senescent macrophages, but higher expression levels of these factors were found after treatment with PDLLA, PN, or CaHA. In addition, after exposure to CM from senescent macrophages treated with PDLLA, PN, or CaHA, senescent endothelial cells expressed higher levels of VEGF receptor 2 (VEGFR2), PI3K, phosphorylated AKT (pAKT), and phosphorylated ERK1/2 (pERK1/2) and demonstrated greater capacities for cell migration, cell proliferation, and tube formation. Based on the levels of 4-hydroxy-2-nonenal, the oxidative stress level was lower in the skin of aged mice injected with PDLLA, PN, or CaHA, while the tumor growth factor (TGF)-β1, TGF-β2, and TGF-β3 expression levels; the density of collagen fibers; and the skin elasticity were higher in the skin of aged mice injected with PDLLA, PN, or CaHA. These effects were greater in PDLLA than in PN or CaHA. In conclusion, our results are consistent with the hypothesis that PDLLA stimulates angiogenesis, leading to the rejuvenation of aged skin. Our study is the first to show that PDLLA, PN, or CaHA can result in angiogenesis in the aged skin, possibly by increasing the levels of HSP90, HIF-1α, and VEGF and increasing collagen synthesis.

Multiple branch retinal artery occlusions following the new facial cosmetic filler (Poly-D, L-lactic Acid) injection a case report

BACKGROUND

Poly-D, L-lactic acid is (PDLLA) a new cosmetic filler. We reported the first case of PDLLA-related devastating complication of multiple branch retinal artery occlusion (BRAO).

CASE PRESENTATION

A 23-year-old female had sudden blindness after injection of PDLLA at the glabella. After emergency intraocular pressure-lowering medicine, ocular massage, steroid pulse therapy, heparin and alprostadil infusion, and subsequent treatments including acupuncture and 40 sessions of hyperbaric oxygen therapy, her best-corrected visual acuity improved from hand motion at 30 cm to 0.3 within 2 months.

CONCLUSION

Although safety of PDLLA was evaluated in animal studies and in 16,000 human cases, it could still cause rare but devastating retinal artery occlusion as in the present case. Proper and immediate therapies could still improve patient's vision and scotoma. Surgeons should keep in mind the possibility of iatrogenic filler-related retinal artery occlusion.

Collagen and the effect of poly-l-lactic acid based materials on its synthesis

Collagen is an important protein in various biological functions such as providing elasticity and waterproofing to the skin, structural stability to the cells in connective tissues (e.g. tendons, and bone) and stabilisation of atherosclerotic plaques. Collagen as a peptide with a peculiar triple helical structure is majorly composed of glycine and proline amino acids and is synthesised by fibroblasts via intracellular and extracellular mechanisms. Collagen plays an important role in wound healing, bone repair and plaque build-up during atherosclerosis. Various factors such as interleukins, insulin-like growth factor-I, nicotine, and glucose have been shown to influence collagen synthesis. This paper provides an overview of collagen structure, synthesis mechanisms, and the parameters that stimulate those mechanisms. Poly-l-lactic acid as a well-known biocompatible and biodegradable polymer has proved to stimulate collagen synthesis in various physical forms. As such, in this review special emphasis is laid on the effects of poly-l-lactic acid as well as its mechanism of action on collagen synthesis.

Reconstitution of Injectable Poly-d,l-lactic Acid: Efficacy of Different Diluents and a New Accelerating Method

Injectable poly-d,l-lactic acid (PDLLA) is a new collagen-stimulating filler containing PDLLA microspheres and carboxymethyl cellulose. It is available as a lyophilized powder that must be reconstituted with a diluent before administration. The aims of this study were to investigate the efficacy of different diluents and a new accelerating “back-and-forth” method.