Collagen Stimulators in Body Applications: A Review Focused on Poly-L-Lactic Acid (PLLA)

The AestheBody Guide: A Practical Approach to AestheFill Injection Beyond the Face

The demand for nonsurgical body rejuvenation treatments is steadily increasing. Among the available options, biostimulators have emerged as a significant and impactful solution. Common off-face areas treatable with biostimulators include the neck, chest, abdomen, buttocks, arms, thighs, knees, and hands. Since these regions often involve large skin surfaces, treatment typically requires a higher number of vials. Therefore, each step must be carefully planned to minimize product waste. AestheFill, a biostimulator based on poly-D,L-lactic acid, stands out as a versatile filler for diverse indications. In this article, we propose the "AestheBody Guide," a practical approach to AestheFill injection for body skin rejuvenation.Level of Evidence V 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 .

Hydrogel promotes bone regeneration through various mechanisms: a review

Large defects in bone tissue due to trauma, tumors, or developmental abnormalities usually require surgical treatment for repair. Numerous studies have shown that current bone repair and regeneration treatments have certain complications and limitations. With the in-depth understanding of bone regeneration mechanisms and biological tissue materials, a variety of materials with desirable physicochemical properties and biological functions have emerged in the field of bone regeneration in recent years. Among them, hydrogels have been widely used in bone regeneration research due to their biocompatibility, unique swelling properties, and ease of fabrication. In this paper, the development and classification of hydrogels were introduced, and the mechanism of hydrogels in promoting bone regeneration was described in detail, including the promotion of bone marrow mesenchymal stem cell differentiation, the promotion of angiogenesis, the enhancement of the activity of bone morphogenetic proteins, and the regulation of the microenvironment of bone regeneration tissues. In addition, the future research direction of hydrogel in bone tissue engineering was discussed.

In Vivo Effectiveness of Poly-L-Lactic Acid Microsphere Dermal Fillers in Stimulating Collagen Synthesis

BACKGROUND

Intradermal injections of fillers such as poly-L-lactic acid (PLLA) microspheres and hyaluronic acid (HA) offer the possibility of skin rejuvenation. However, the biological effects of these fillers and the mechanisms underlying collagen synthesis have not been fully elucidated. We investigated the histological effects of PLLA microsphere fillers on the rat dermis.

METHODS

PLLA microspheres were used as the experimental group, while HA and saline served as the positive and negative controls, respectively. Equal doses of cross-linked HA, saline, and PLLA microspheres were intradermally injected into the backs of male Sprague-Dawley rats. Biopsy specimens were collected and histologically analyzed using hematoxylin and eosin, Ki-67, alpha-smooth muscle actin, Herovici, and Sirius scarlet staining. Immunofluorescence staining for types I and III collagen, CD68, and CD90 was also performed. Quantitative data were statistically analyzed using a two-way analysis of variance.

RESULTS

PLLA microspheres increased collagen type I and III levels and maintained tissue homeostasis in rat dermis. The PLLA microspheres primarily stimulated type III collagen in the early stage, whereas type I collagen was predominantly stimulated in the later stages. After the PLLA microspheres were injected into the dermal tissue, early fibroblasts and macrophages surrounded the microspheres, followed by the transformation of fibroblasts into myofibroblasts, which positively affected the production of type I collagen. Notably, HA demonstrated a significant stimulatory effect on type I collagen synthesis (P < 0.05) but showed no statistically significant impact on type III collagen production. In contrast, the saline control group failed to show any measurable increase in either collagen subtype throughout the experimental period.

CONCLUSIONS

HA and PLLA microspheres effectively increased type I collagen levels and maintained dermal tissue homeostasis. PLLA microspheres can be used as the main ingredient in intradermal collagen regenerative fillers due to their long degradation time and lasting effects.

LEVEL OF EVIDENCE V

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 .

An Assessment and Comparison of Adverse Effect Rates in Differing Absorbable Thread Lift Suture Materials

BACKGROUND

Thread lifting, a minimally invasive alternative to facial rhytidectomy, has shifted from using nonabsorbable to absorbable sutures. Although many thread lift options exist, the impact of these different properties on complication rates remains unclear.

OBJECTIVE

To systematically compare thread lift complication rates across different suture materials, textures, fixation methods, and lift locations.

MATERIALS/METHODS

A systematic review was conducted through February 2024, following PRISMA guidelines, using multiple databases. The study focused on absorbable sutures, excluding nonabsorbable materials. Statistical analysis used Chi-Square tests with Bonferroni correction.

RESULTS

Nineteen studies, encompassing 1,406 patients, met inclusion criteria. A total of 876 complications were reported. Ecchymosis (19.49%), swelling (16.79%), and tenderness (9.96%) were the most frequent complications, while hematoma (0.64%), paresthesia (1.14%), and infection (2.49%) were least frequent. Complications varied significantly among the studied factors. Swelling and ecchymosis were more associated with polycaprolactone sutures, barbed threads, and midface lifts. Barbed threads were associated with more complications than smooth or coned threads, as were floating threads compared with fixed threads.

CONCLUSION

Variations in thread lift suture materials and fixation technique were associated with different complication rates. Thread lifts using absorbable sutures exhibited complication rates under 5%, suggesting a generally favorable safety profile.

In Vitro Evaluation and Clinical Effects of a Regenerative Complex with Non-Cross-Linked Hyaluronic Acid and a High-Molecular-Weight Polynucleotide for Periorbital Treatment

Skin aging is a complex and multifactorial process influenced by both intrinsic and extrinsic factors. The periorbital area of the face is particularly susceptible to premature aging signs due to its delicate skin structure, and is a major concern for many individuals. While hyaluronic acid (HA)-based dermal filler products are commonly used for periorbital rejuvenation, novel approaches to effectively locally address the visible signs of aging are available. This study aimed to investigate Innovyal Regenerative Action (IRA), an injectable polynucleotide-HA (PN-HA) regenerative complex designed for periocular prejuvenation. Firstly, PN-HA was compared to other commercially available HA-based dermbooster products (Profhilo®, Suisselle Cellbooster® Glow, and NCTF® 135 HA) in terms of rheological properties, in vitro antioxidant capacity, and total collagen production stimulation in human fibroblasts. Secondly, the clinical effects of the IRA PN-HA complex were evaluated in two case reports (monotherapy for periorbital prejuvenation). It was shown that the PN-HA complex outperformed its comparators in terms of relative rheological behavior (biophysical attributes normalized to polymer contents), intrinsic antioxidant activity (CUPRAC, FRAP, and ORAC assays), as well as total collagen level induction (72-h in vitro dermal fibroblast induction model). Generally, the results of this study provided mechanistic and preliminary clinical insights into the potential benefits of the IRA PN-HA complex for periocular cutaneous treatment. Overall, it was underscored that combining the structural support and regenerative properties of PN with the hydrating and volumizing effects of HA bares tangible potential for multifactorial skin quality enhancement and for periocular prejuvenation in particular.

A coaxial electrospun PLLA/PPDO/NAR mesh for abdominal wall hernia repair

This study aims to employ poly-L-lactic acid (PLLA) and poly(p-dioxanone) (PPDO), loaded with naringin (NAR) to fabricate a functionalized degradable mesh which can promote abdominal wall hernia (AWH) repair. Three meshes named PPDO, PLLA/PPDO, and PLLA/PPDO/NAR were fabricated by electrospinning. The physical and chemical properties of the meshes were evaluated from the aspects of morphology, wettability, chemical composition, mechanical properties, andin vitrodegradation. Then, the meshes were implanted into rats to evaluate their repair effects on abdominal wall defect models. The mechanical properties of PLLA/PPDO/NAR mesh were superior to the other two meshes, with a fixed tensile strength of 36.47 ± 2.40 N cm-1and an elongation at break of 287.98% ± 51.67%, which adequately met the mechanical strength required for the human abdominal wall. The core-shell structure effectively delayed the degradation of PLLA/PPDO as well as PLLA/PPDO/NAR mesh, and drug release of PLLA/PPDO/NAR mesh. On the 7th, 14th, and 28th day after implantation, more neovascularization and tissue formation were observed in the PLLA/PPDO/NAR group and the newborn collagen was arranged in a regular and neat manner compared to the other two groups. The immunohistochemical results showed that the PLLA/PPDO/NAR mesh promoted abdominal wall repair by inhibiting the expression of matrix metalloproteinase2 as well as interleukin-6, and increasing the expression of vascular endothelial growth factor. The PLLA/PPDO/NAR mesh is promising for application in AWH repair.

Poly l-Lactic Acid Nanofiber Membrane Effectively Inhibits Liver Cancer Cells Growth and Prevents Postoperative Residual Cancer Recurrence

Electrospun nanocarrier systems, widely employed in the medical field, exhibit the capability to encapsulate multiple drugs and mitigate complications. Doxorubicin hydrochloride (DOX) represents a frequently utilized chemotherapeutic agent for liver cancer patients. Sodium bicarbonate (SB) serves to neutralize the acidic tumor microenvironment, while ibuprofen (IBU) attenuates inflammatory factor production. The combination of these three commonly used drugs facilitates antitumor efficacy and relapse prevention. Composite fibrous membranes were prepared by incorporating the antitumor drug DOX into MSN, which was then codispersed with IBU in a poly l-lactic acid (PLLA) electrospinning solution after acid sensitization using SB. The resulting membrane was characterized using transmission electron microscopy and scanning electron microscopy. The toxic effect of this fibrous membrane and its pro-apoptotic effect on tumor cells were evaluated, along with the expression of cell proliferation-related factors, immune/inflammatory factors, and apoptosis-related factors. Immunohistochemistry and HE staining confirmed its ability to inhibit recurrence of postoperative residual cancer without causing toxicity to vital organs. The PLLA-MSN@DOX-SB-IBU nanofibrous membrane not only mitigates the cardiotoxicity associated with DOX but also inhibits tumor cell proliferation and enhances the tumor microenvironment, demonstrating significant antitumor efficacy. Furthermore, it effectively prevents the recurrence of residual cancer postsurgery while exhibiting excellent biocompatibility. The PLLA-MSN@DOX-SB-IBU nanofibrous membrane demonstrates significant potential in impeding the progression of hepatocellular carcinoma and mitigating the recurrence of residual cancer following surgical intervention for hepatocellular carcinoma.

Treatment of the Induration of the Soft Tissue of the Lower Eyelids After Accidental Oil Injections

Injection cosmetic procedures have shown rapid continuing growth in the last 2 decades. Various substances are injected into the periorbital region for skin quality increase and correction of tear trough deformity, including hyaluronic acid, peptides, collagen, and others. Sometimes patients get accidentally injected with different substances that are not approved for cosmetic treatment in this anatomic area. The author presents a case of a 51-year-old woman, injected with unknown oil solution into the lower eyelid skin by the local dermatologist. Inflammation and induration of the skin of the lower periorbital region have occurred after these injections. The patient was treated conservatively until the acute process stopped, and then surgical correction was performed to correct skin and orbicularis oculi muscle induration changes. Surgical treatment included direct oil cyst excision and removal after injection changed tissues between skin and orbicularis oculi muscle. The patient was observed for scheduled appointments and conservative treatment to prevent unfavorable scar formation and lower eyelid deformity. Although different kinds of oil substances are not approved for skin injections for cosmetic purposes, accidental injections occur and may lead to terrible results. Methods to correct eyelid deformity after oil solution injections are not presented in the literature. In this article, the author presents a case report with the method of correction of induration of soft tissues of the lower eyelids occurring after oil injections. Although cases like this are rare, they require correct surgical solution to provide a good aesthetic result after the treatment.

Multicentric Retrospective Study on Safety and Efficacy of a Novel Injectable Poly-l-Lactic Acid for Buttocks Recontouring

BACKGROUND

Poly-l-lactic acid (PLLA) injectables have gained increasing attention in aesthetic medicine due to their biocompatibility and long-lasting effects. Although their primary application centers around facial rejuvenation, their potential for off-label use in other body areas has been investigated, demonstrating promising outcomes in terms of both efficacy and safety.

AIM

This study aims to assess the safety and efficacy of a novel 630 mg PLLA-based filler (GANA X), in buttocks treatment.

METHODS

Six physicians treated 51 patients for buttock aesthetic treatment across six different medical facilities in Italy. A survey was filled by both physicians and patients regarding treatment safety, efficacy, and change in quality of life.

RESULTS

We reported minor or mild adverse events, self-resolving within the next few days. Both physicians and patients confirmed notable aesthetic improvements following treatment, varying from moderate to significant enhancement. These effects endured throughout follow-up visits spanning up to 24 months. Patient-reported outcomes indicated elevated self-esteem and improved quality of life posttreatment.

CONCLUSIONS

The high level of satisfaction reported by both physicians and patients highlights the efficacy and tolerability of GANA X filler for buttocks treatment, encouraging their use and research for off-label body areas.

Synthetic Dermal Fillers in Treating Acne Scars: A Comparative Systematic Review

BACKGROUND

Acne is a common condition observed in adolescents and in most severe acne the scars develop. There are numerous treatment options for acne scars. However, no standardized guidelines have been established to guide physicians in the optimal treatment of acne scars.

AIMS

The objective of this systematic review is to evaluate the existing evidence on various fillers used for the treatment of acne scars and to compare their effectiveness with one another.

METHODS

The study was designed following PRISMA guidelines, and the information was retrieved in May 2024 using the PubMed database and ClinicalTrials.gov registry. The inclusion criteria were that studies involving patients of any age or gender with acne scars of any type treated with synthetic dermal fillers, and studies published in English. The exclusion criteria were studies with less than 10 participants and studies that did not use synthetic dermal fillers. To assess the risk of bias in the included studies, the Cochrane Collaboration's Risk of Bias tool was used for randomized controlled trials, and in observational studies, the Newcastle-Ottawa Scale was used.

RESULTS

Twenty-six studies were included with a total of 1121 participants. Fourteen studies evaluated HA on 372 subjects, five studies focused on PMMA on 305 subjects, four on CaHA on 392 subjects, two on PLLA on 42 subjects, and one on PCL on 10 subjects.

CONCLUSIONS

Most of the studies included in this review were of low quality, as indicated by their scores on quality assessments, lack of high-quality RCTs, and small sample sizes. Future research should focus on conducting randomized, controlled, split-face studies with an adequate number of participants and a detailed examination of different scar subtypes.

Poly-L-Lactic Acid Reduces the Volume of Dermal Adipose Tissue Through its Metabolite Lactate

Poly-L-lactic acid (PLLA), a well-established biostimulator that induces collagenases, is widely used among clinical practice to treat skin aging. However, the precise regulatory effect of PLLA on different dermal cell subsets beyond fibroblast has not been fully elucidated. In this study, we constructed in vivo PLLA injection and in vitro PLLA-adipocyte co-culture models to analyze the regulatory effects of PLLA on the volume, differentiation, lipolysis, and thermogenic capacity of dermal adipocyte. We found that PLLA injection significantly reduced the thickness of dermal fat in mice. In co-culture assay, PLLA showed no effect on adipogenesis, but stimulated the lipolysis activity. Interestingly, PLLA also enhanced the differentiation of fat cells into beige fat cells, which possess higher thermogenic capacity. In mechanical study, we blocked adipocyte lactate uptake with a monocarboxylate transporter (MCT1/4) inhibitor and found that the regulatory effect of PLLA on dermal adipocyte relies on its metabolite lactate. In summary, our results suggest that PLLA has complex regulatory effects on the dermal cells, and its ability to improve skin aging is not fully attributed to stimulating collagen synthesis, but also partially involves adipocytes.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 .

Safety and effectiveness results of an innovative injectable poly-L-lactic acid-based collagen stimulator (Lanluma®)-Clinical outcomes at 9 months in a post-market study

BACKGROUND

Injectable fillers for soft tissue augmentation stand out as one of the most favored procedures in the field of aesthetic medicine, especially in addressing the clinical signs of skin aging. Among soft tissue fillers, non-permanent fillers have been safely used in numerous medical applications for several decades.

AIMS

The aim of this post-market observational, open-label, uncontrolled, multicentered, prospective study (PMS) was to evaluate the effects of an injectable poly-L-lactic acid-based collagen stimulator (Lanluma®, the study product).

PARTICIPANTS/METHODS

This analysis is based on the clinical outcomes data (safety and effectiveness) collected from investigators and participants between the first injection (T0, September 2022) and 9 months thereafter (T3, June 2023) in the treatment of five body-contouring areas.

RESULTS

Overall, 70 participants had 99 treatment sessions of the neck (31%), upper arm (20%), hand (17%), thigh (16%) and décolleté (15%). Lumps (neck, upper arm, hand) and nodules (neck, hand, thigh) were the most frequent adverse events (AEs) reported by investigators. All were treatment related. None were serious, severe or fatal. No AEs were reported following treatment of the décolleté. Both investigators and participants reported high levels of satisfaction during the nine-month follow-up period with the treatments in five body areas.

CONCLUSIONS

These positive clinical outcomes can be attributed to a proper implementation of best practices and recommendations, and the rheological properties of the study product. This 9-month follow-up analysis should be reconsidered in light of the study's objectives for the final analysis at the 25-month follow-up.

Short-Term Effects of Poly-L-Lactic Acid-b-Polyethylene Glycol Microsphere Injection on Different Adipose Tissue Types in Rats

Background

Wrinkles and sagging, characteristics of aging, are associated with reductions in collagen and fat. Poly-L-lactic acid (PLLA) is widely used clinically as a tissue filler owing to its good biocompatibility and ability to improve wrinkles and signs of aging. Despite extensive studies of the mechanism of action of PLLA when used as a dermal filler, few studies have examined its effects on adipose tissue.

Objectives

The short-term effects of PLLA-b-polyethylene glycol (PEG) microspheres implanted in subcutaneous back adipose tissue (BAT) and visceral epididymal adipose tissue (EAT) of rats were examined.

Methods

The authors divided 15 male Sprague-Dawley rats into 5 groups based on implantation time, and PLLA-b-PEG microspheres were implanted into the BAT (3 groups were sampled at 6, 8, and 12 weeks) and EAT (2 groups were sampled at 6 and 12 weeks) of rats. Tissue samples were collected at different time points postimplantation and subjected to histological analyses using hematoxylin and eosin, Masson's trichrome, and immunofluorescence staining.

Results

Implantation of PLLA-b-PEG microspheres into different adipose tissues resulted in a mild and persistent inflammatory reaction, increased fibrous connective tissue, and noticeable collagen regeneration. Immunofluorescence showed the upregulation of uncoupling protein (UCP) 1 and UCP2 in the visceral adipose tissue surrounding the implant.

Conclusions

PLLA-b-PEG microspheres exhibited good tissue compatibility and induced an increase in fibrous connective tissue postimplantation, potentially mitigating oxidative damage and improving adipose tissue quality.

Level of Evidence 5 Therapeutic

Comparison of three elements (In, Sn, and Sb) in the same period as catalysts in the ring-opening polymerization of l-lactide: from amorphous to semicrystalline polyesters

The ring-opening polymerization (ROP) of l-lactide (l-LA) is the main method for synthesizing poly(l-lactide) (PLLA), in which choosing the catalyst is one of the most important parameters. In this work, we focused on the systematic study of catalysts based on p-block elements from period 5, such as indium(iii), tin(ii), tin(iv) and antimony(iii) acetates, which displayed contrasting performances influenced by the oxidation state of the metal center. Analysis of the obtained oligomers by different techniques, including nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), polarized optical microscopy (POM) and matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), revealed the selectivity of each catalyst toward the ROP of l-LA. Tin(ii) acetate showed the best performance, making it the best catalyst of this series for synthesizing PLLA. Indium(iii) and tin(ii) acetates induced an amorphous and semicrystalline polyester, respectively. The kinetic study evidenced the excellent performance of tin(ii) acetate in the ROP of l-LA. This catalyst reached high conversions in a quarter of the total reaction time, positioning it as the most catalytically active of the selected p-block acetate catalysts. Finally, the coordination-insertion mechanism by the catalyst in the initiation step was corroborated through the development of a mechanistic study applying the density functional theory (DFT).

Tailoring biomaterials for skin anti-aging

Skin aging is the phenomenon of degenerative changes in the structure and function of skin tissues over time and is manifested by a gradual loss of skin elasticity and firmness, an increased number of wrinkles, and hyperpigmentation. Skin anti-aging refers to a reduction in the skin aging phenomenon through medical cosmetic technologies. In recent years, new biomaterials have been continuously developed for improving the appearance of the skin through mechanical tissue filling, regulating collagen synthesis and degradation, inhibiting pigmentation, and repairing the skin barrier. This review summarizes the mechanisms associated with skin aging, describes the biomaterials that are commonly used in medical aesthetics and their possible modes of action, and discusses the application strategies of biomaterials in this area. Moreover, the synergistic effects of such biomaterials and other active ingredients, such as stem cells, exosomes, growth factors, and antioxidants, on tissue regeneration and anti-aging are evaluated. Finally, the possible challenges and development prospects of biomaterials in the field of anti-aging are discussed, and novel ideas for future innovations in this area are summarized.

Manufacturing Process of Hyaluronic Acid Dermal Fillers

Hyaluronic acid (HA) fillers are extensively utilized in aesthetic medicine due to their biocompatibility, reversibility, and effectiveness in enhancing skin hydration, volume, and overall appearance. These fillers are predominantly produced through microbial fermentation, followed by a critical cross-linking process that enhances their longevity by resisting enzymatic degradation. This review provides a thorough examination of the manufacturing processes that differentiate HA fillers, with particular attention to the distinctions between biphasic and monophasic variants. Unlike previous studies, this review emphasizes the specific cross-linking techniques and their substantial impact on the fillers' rheological properties, such as elasticity and cohesiveness, which are crucial to their clinical performance and patient outcomes. Additionally, the review offers a comprehensive comparison of HA fillers with non-HA alternatives, including calcium hydroxylapatite, poly-l-lactic acid, and polymethyl methacrylate, highlighting the unique advantages and potential complications associated with each type. By presenting novel insights into the latest advancements and challenges in filler technology, this review aims to provide clinicians with a deeper understanding of filler properties, thereby guiding them in making informed decisions to optimize patient safety and aesthetic results.

Injectable and biodegradable collagen-chitosan microspheres for enhanced skin regeneration

Skin aging is influenced by both external environmental factors and intrinsic biological mechanisms. Traditional microsphere implants aim to rejuvenate aging skin through collagen regeneration, yet their non-biodegradability and risk of granuloma formation often limit their effectiveness. In this study, we developed novel, injectable, highly bioactive, and degradable collagen-chitosan double-crosslinked composite microspheres for skin rejuvenation. The microspheres demonstrated excellent injectability, requiring an injection force of only 0.9 N, and significant biodegradability, effectively degraded in solutions containing phosphate buffer, type I collagenase, and pepsin. In addition, the microspheres exhibited excellent biocompatibility and bioactivity, significantly promoting the proliferation, adhesion, and migration of human foreskin fibroblast-1 (HFF-1) cells. In a photoaged mouse skin model, the implantation of microspheres significantly enhanced dermal density and skin elasticity while reducing transepidermal water loss. Importantly, the implant promoted the regeneration of collagen fibers. This study suggests that collagen-chitosan double-crosslinked composite microspheres hold significant potential for skin rejuvenation treatments.

Efficacy and Safety of Poly-l-Lactic Acid in Facial Aesthetics: A Systematic Review

The primary objective of this systematic review study was to investigate the effectiveness, durability, and adverse events of PLLA treatment for aesthetic indications. The search strategy was performed in MEDLINE (Ovid). The electronic literature search of five databases was performed, from the inception of the databases until the 12th of February 2024. This was to identify randomized clinical trials that assessed PLLA treatment in adult individuals exhibiting facial aging and/or facial lipoatrophy. Risk of bias was assessed using the Cochrane Risk-of-Bias Tool for Randomized Trials (RoB 2). Eleven RCTs out of 1467 identified citations were included. Four studies showed increased dermal thickness, significant improvement in facial lipoatrophy severity and aesthetic clinical scores, after PLLA treatment with its effects sustained for at least 25 months. Two studies demonstrated the superiority of PLLA over injectable human collagen. Also, three studies showed positive results favoring PLLA when compared with PH gel in lipoatrophy severity, transepidermal water loss, skin quality, elasticity, and patient satisfaction. All adverse events were mild-to-moderate in intensity, and the main ones worth noting were bruising, hematoma, tenderness, nodules, and edema. Five out of eleven studies were considered having high risk of bias. The evidence on the effectiveness and safety of PLLA for facial rejuvenation is of low quality; thus, the reported high effectiveness, safety, and long-lasting effects for this purpose should be further investigated.

Potential Application of Camel Milk as a Therapeutic Ingredient in Bath Soaps and Shampoos

The increasing worldwide market for natural-ingredient-based cosmetic toiletries is fuelled by the awareness of the dangers of synthetic cosmetics and benefits of natural-based cosmetics on the skincare and management of skin disorders. Besides naturally formulated cosmetics being biodegradable, they also contain ingredients which are chemically beneficial to human skin. Milk-based cosmetics are very promising since milk is rich in essential components such as lactoferrins, vitamins, and lactic acids, which have shown therapeutic properties against disorders such as skin cancer, acne scars, and dandruff. One of the milk that is very promising in the cosmetics industry is the camel milk. Currently, there is limited information in literature regarding the use of camel milk in cosmetics and their benefits. Camel milk stands out from bovine milk following its unique therapeutic properties and chemical composition, making it a potential ingredient for skincare and haircare products such as bath soaps and shampoos. The aim of this paper is to review the available literature on camel milk composition and evaluate the contribution of camel milk constituents to cosmetics.

Clinical efficacy and safety of composite non-cross-linked hyaluronic acid for treating tear trough-lower eyelid bag deformity

BACKGROUND

Tear trough-eye bag deformities may appear in young Asian patients due to the weak support of their facial skeletons. For these patients with better periorbital skin elasticity, the injection may be more suitable than surgery for treating tear trough-lower eyelid bag deformity.

AIMS

Identify the clinical efficacy and safety of non-cross-linked HA in the treatment of tear trough-lower eyelid bag deformity.

METHODS

In this study, we analyzed pre- and postinjection photographs of 55 patients treated with non-cross-linked hyaluronic acid (HA) for tear trough-lower eyelid bag deformity.

RESULTS

The mean [SD] scores of modified Goldberg score suggested that the most significant improvement of preoperative and postoperative scores was in tear trough depression, followed by infraorbital triangular depression, orbital fat prolapse, loss of skin elasticity, and skin transparency. Only transient localized complications were observed, including bruising, swelling, and erythema. There were no serious complications, such as skin necrosis or visual impairment.

CONCLUSIONS

Our study confirmed the beneficial efficacy and minor complications of composite non-cross-linked HA for the treatment of tear trough-lower eyelid bag deformity.

A systematic review of Radiesse® (calcium hydroxylapatite): evidence and recommendations for the body

A filler composed of calcium hydroxylapatite and carboxymethylcellulose gel (CaHA/CMC) has been shown to possess biostimulatory and skin-tightening properties that have been applied not just to the face but also to the body to boost rejuvenation. Recently, evidence and recommendations for CaHA/CMC treatment of the face have been provided, but they are still lacking in terms of body treatment. This article aims to perform a systematic review of the literature on CaHA/CMC applications on the body and provide evidence from the literature. Currently, the only FDA-approved indication on the body is treating the hands and a recent European Union Medical Device Regulation approval has been released for decolletage treatment. The application of hyperdilutions on the neck, feet, arms, thighs, abdomen, and other body parts has been proven to provide a skin-tightening effect. However, despite their wide use with a good safety profile in clinical practice, recent trends and guidelines of diluted and hyperdiluted CaHA/CMC have yet to be supported by randomized controlled trials.

Analysis of the Thigh Aesthetic Profiles: One of Physical Ideal Body Proportions

BACKGROUND

The contour of the thigh is increasingly being recognized as crucial component of the ideal human physique, giving rise to heightened interest in attaining the perfect thigh profile. Notwithstanding, the contemporary landscape of cosmetic surgery appears to be bereft of efficient and precise objective methodologies to evaluate the outcomes of thigh contouring treatments. The present study is aimed to investigate the aesthetic appeal of varying thigh contours, employing specialized software as an indispensable instrument for quantitative and qualitative analysis.

METHODS

Standardized photographs of the lower body were obtained from a sample of 200 healthy volunteers. A linear analysis was conducted, examining aspects such as the vertical length and transvers width of the thigh, as well as angular measurements including the posterior gluteal angle (PGA) and lateral angle thigh (LAT). Variables relating to thigh measurements and body mass index (BMI) were documented, with the relationships between them ascertained through Pearson's correlation and regression analysis.

RESULTS

In males, the LAT was measured at 168 ± 3.9, and the PGA at 170 ± 3.4, while in females, these measurements were 166 ± 2.8 ve 166 ± 2.8, respectively. Linear analyses, including the vertical length of thigh (VLT), transverse width of thigh (TWT), lateral width (LW), and posterior width (PW), were conducted. Based on the LW inferior/LW superior ratio values, the most commonly observed thigh types were Type III (0.90) at 45% and Type II (0.85) at 24.75% while the least common was Type V at 4% (0.99). PW inferior/PW superior was 84.7%. The PWI/PWS ratio was highest for Type V, at 0.99, accounting for 84.70% of the total. Furthermore, an increase in the LWI/LWS ratio leads to an increase in the PWI/PWS ratio.  The frequency of the VLT/TW1 ratio 0.31-0.35 (Type 3) was found to be on the left side and Type 4 on the right side. A strong correlation was found between BMI and all thigh indexes, with a significant positive correlation between the index and factors tied to the buttocks and upper thigh.

CONCLUSIONS

The concept of an ideal thigh may vary based on an individual's gender, race, country of residence, and self-esteem, aiming to achieve a more natural silhouette. Focusing on the different ratios of hip and thigh varieties in the study is quite intriguing. Further inquiry and rigorous exploration are warranted to delineate the optimal techniques and methodologies for attaining ideal thigh proportions.

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 .

Poly-l-lactic acid microspheres delay aging of epidermal stem cells in rat skin

Objective

Injectable skin fillers offer a wider range of options for cutaneous anti-aging and facial rejuvenation. PLLA microspheres are increasingly favored as degradable and long-lasting fillers. The present study focused solely on the effect of PLLA on dermal collagen, without investigating its impact on the epidermis. In this study, we investigated the effects of PLLA microspheres on epidermal stem cells (EpiSCs).

Methods

Different concentrations of PLLA microspheres on epidermal stem cells (EpiSCs) in vitro through culture, and identification of primary rat EpiSCs. CCK-8 detection, apoptosis staining, flow cytometry, Transwell assay, wound healing assay, q-PCR analysis, and immunofluorescence staining were used to detect the effects of PLLA on EpiSCs. Furthermore, we observed the effect on the epidermis by injecting PLLA into the dermis of the rat skin in vivo.

Results

PLLA microspheres promote cell proliferation and migration while delaying cell senescence and maintaining its stemness. In vitro, Intradermal injection of PLLA microspheres in the rat back skin resulted in delayed aging, as evidenced by histological and immunohistochemical staining of the skin at 2, 4, and 12 weeks of follow-up.

Conclusion

This study showed the positive effects of PLLA on rat epidermis and EpiSCs, while providing novel insights into the anti-aging mechanism of PLLA.

Ellansé: Advanced Technology and Advantageous Selection of New Collagen Stimulating Agents for Face Rejuvenation

Facial injections have a comparative mature market and system in China, but all kinds of injection materials have their own advantages and disadvantages, even hyaluronic acid, as the most common injection material, can form an unnatural stiffness after injection. Currently, Ellansé, a biodegradable collagen stimulator, has shown superior aesthetic results while ensuring safety and naturalness, making it a more preferable choice for a variety of facial injections. The purpose of this review is to introduce the features and benefits of Ellansé, so that doctors in the field can better understand and learn how to use it properly and minimize the risk of complications, and have a better choice for the medical aesthetic field in China in numerous aspects. The papers with the keyword "Ellansé" is very few in number, and there is a lack of systematic overview. Ellansé itself has unique advantages for the Chinese population, as it is an attractive option for the treatment of aging face due to high patient satisfaction, long-lasting results and low side effects (Guo et al. in J Cosmet Dermatol 21(5):1959-1966, 2022). More clinical data will be available in the future to confirm its performance and longevity in various sites. LEVEL OF EVIDENCE V: 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 .

A Clinical Guide to the Treatment of Cellulite and Comprehensive Review of the Etiology, Pathophysiology, and Utility of Intervention

INTRODUCTION

Cellulite is a common esthetic concern affecting most women. Despite its prevalence, there is no consensus on the optimal treatment approach for cellulite, partly due to the complex and multifactorial nature of its pathophysiology. Understanding the underlying biological processes along with available treatment options is important to be able to effectively counsel patients on effective management of this condition. This review aims to focus on high-quality evidence behind pathophysiology of cellulite, severity and grading, and its available treatment options.

METHODS

A comprehensive review of the literature was performed using PubMed and Embase databases. Manuscripts that provided objective data with respect to pathophysiology, grading scales, and applications of treatment options were utilized.

RESULTS

Using the existing CSS classification, an evidence-based algorithm is proposed for treatment of cellulite. Mild cellulite is best served with lifestyle modifications such as healthy diet, hydration, and exercise. Use of topicals in mild cellulite patients as adjuncts to lifestyle modifications have the highest efficacy, although there are inconsistent data on topical treatments. Moderate cellulite is best targeted with noninvasive treatment options including laser therapy, radiofrequency, and ultrasound. Radiofrequency demonstrates the strongest efficacy in the current peer-reviewed literature. Severe cellulite is recommended to be treated with minimally invasive approaches such as subcision and injectables.

CONCLUSION

Cellulite is a challenging cosmetic problem to treat, and thus multimodal treatment options should be considered in an attempt to achieve optimal outcomes and patient satisfaction. As the pathophysiology of cellulite is further elucidated, more targeted treatments may be developed in the future.

LEVEL OF EVIDENCE V

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 .

Advancements in Regenerative Medicine for Aesthetic Dermatology: A Comprehensive Review and Future Trends

The growing interest in maintaining a youthful appearance has encouraged an accelerated development of innovative, minimally invasive aesthetic treatments for facial rejuvenation and regeneration. The close correlation between tissue repair, regeneration, and aging has paved the way for the application of regenerative medicine principles in cosmetic dermatology. The theoretical substrates of regenerative medicine applications in dermo-aesthetics are plentiful. However, regenerative dermatology is an emerging field and needs more data and in vivo trials to reach a consensus on the standardization of methods. In this review, we summarize the principles of regenerative medicine and techniques as they apply to cosmetic dermatology, suggesting unexplored fields and future directions.

Application of PLLA (Poly-L-Lactic acid) for rejuvenation and reproduction of facial cutaneous tissue in aesthetics: A review

Poly-L-lactin acid (PLLA) has been widely used in the field of bio-medicine. In 2004, as an injectable material, PLLA was approved by the FDA to treat AIDS-related facial atrophy. Since then, several injectable stuffs containing PLLA have been approved for marketing in various countries and regions. Recently, PLLA has often been used to treat facial rejuvenation problems like cutaneous depressions and static wrinkles which always induce unsatisfactory facial expression. This review introduces the physicochemical properties, regeneration stimulating mechanism, applications in aesthetics and injectable comorbidity of PLLA.

Subcutaneous Application of a Gelatin/Hyaluronic Acid Hydrogel Induces the Production of Skin Extracellular Matrix

The development of injectable hydrogels with natural biopolymers such as gelatin (Ge) and hyaluronic acid (Ha) is widely performed due to their biocompatibility and biodegradability. The combination of both polymers crosslinked with N-Ethyl-N'-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) can be used as an innovative dermal filler that stimulates fibroblast activity and increases skin elasticity and tightness. Thus, crosslinked Ge/Ha hydrogels with different concentrations of EDC were administered subcutaneously to test their efficacy in young and old rats. At higher EDC concentrations, the viscosity decreases while the particle size of the hydrogels increases. At all concentrations of EDC, amino and carboxyl groups are present. The histological analysis shows an acute inflammatory response, which disappears seven days after application. At one and three months post-treatment, no remains of the hydrogels are found, and the number of fibroblasts increases in all groups in comparison with the control. In addition, the elastic modulus of the skin increases after three months of treatment. Because EDC-crosslinked Ge/Ha hydrogels are biocompatible and induce increased skin tension, fibroblast proliferation, and de novo extracellular matrix production, we propose their use as a treatment to attenuate wrinkles and expression lines.

Cellulite: An Update on Pathogenesis and Management

Cellulite is a common cosmetic concern among postpubertal women. Despite its high prevalence, there have been only a few high-quality studies assessing its exact prevalence, risk factors, and pathophysiologic mechanisms. It has been difficult to achieve long-lasting results with the available treatments, including topical agents, energy-based devices, subcision, and injectables. In this review, the authors summarize the proposed etiologic factors, grading scales, and treatment options. Further well-designed studies are essential to improve our knowledge of the condition and lead to improved treatment strategies.

Body Harmonization: The Definition of a New Concept

Body Harmonization (BHA) is an innovative concept in aesthetics area based on a set of advanced injectable techniques that have shown promising results for body shaping. This is based on procedure combinations indicated to treat body aesthetic dysfunctions, such as localized fat, stretch marks, blemishes, flaccidity, buttocks remodeling, lean mass gain and muscle definition. This study aims to define the clinical concept of BHA, its applications and the main protocols used based on injectable pharmacotherapy. For this purpose, we performed a retrospective review of proven efficient injectable procedures with advanced results for the treatment of body aesthetic disorders, in addition to relying on data obtained from previous clinical experiences. Based on these data, we describe how different compounds can act for treatment of the main body aesthetic dysfunctions, such as lipolytic compounds and collagen biostimulators. In addition, the main application techniques and treatment protocols for each of these dysfunctions were defined. Minimally invasive injectable procedures offer an effective therapeutic option for patients who do not intend to undergo surgical interventions.

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.

Complications of toxins and fillers in facial aesthetics

Dermal filler and botulinum toxin injections are among the most performed non-invasive procedures for rejuvenation and contouring, internationally. Although most dermal fillers and approved botulinum toxins are well tolerated with a high safety profile, adverse events and/or complications can happen. Injection-related sequelae and side effects are usually rare, mild, transient, and self-limiting in nature. However, devastating and life-changing complications, such as intravascular occlusion, skin necrosis, permanent visual impairment, and stroke, have been reported. Risk reduction measures include an in-depth knowledge of anatomy, physiology, and pharmacology, correct patient selection, correct identification of clinical indications, and, fundamentally, the importance of appropriate skill and training. In this paper, some of the complications are discussed and advice on how to minimise adverse events and complications from these injectables is provided.

Poly-L-Lactic acid increases collagen gene expression and synthesis in cultured dermal fibroblast (Hs68) through the TGF-β/Smad pathway

OBJECTIVE

Poly-L-Lactic Acid (PLLA) is a synthetic polymer which possesses biocompatible and biodegradable properties, and is widely used in the clinical filler material. This study focuses on the potential role of PLLA on the collagen production of dermal fibroblasts and its mechanism.

METHODS

The dermal fibroblast Hs60 was treated with different concentration of PLLA. RT-qPCR was conducted for the determination of mRNA levels of collagen type I (COL1) alpha 1 (COL1A1), COL1 alpha 2 (COL1A2), elastin, matrix metalloproteinase 1 (MMP-1), tissue inhibitor of metalloproteinase 1 (TIMP-1), and TIMP-2. Procollagen Type I C-peptide (PIP) enzyme immunoassay (EIA) Kit assay was carried out to analyze procollagen production. Western Blot was employed to examine the effect of PLLA and transforming frown factor (TGF-β) receptor-specific inhibitor (SB431542) on protein levels of COL1A1 and TGF-β/Smad signaling pathway related proteins.

RESULTS

With the increase of PLLA concentration, the production of procollagen gradually increased, and both protein and mRNA levels of COL1A1 and COL1A2 gradually increased (p < 0.001). Elevated PLLA concentrations increased elastin, TIMP-1, and TIMP-2 levels and attenuated MMP-1 expression. PLLA increased TGF-β levels in a dose-dependently manner. p-Smad2 and p-Smad3 protein levels were also increased by PLLA, but the influences were reversed by SB431542 (p < 0.001). Similarly, increased levels of COL1A1, COL1A2, TIMP-1, and TIMP-2 caused by PLLA were significantly inhibited by SB431542, whereas MMP-1 was typically elevated (p < 0.001).

CONCLUSION

Poly-L-Lactic Acid promotes the collagen production of dermal fibroblasts by activating the TGF-β/Smad signaling pathway. The findings may lay a foundation for clinical material applications of PLLA.

How Nutrition and Supplements Impact Aesthetic Outcomes

Nutraceuticals, nutritional supplements, and the diet industry often provide misleading information, make faulty promises, and may also support profit over consumer safety. Furthermore, the U.S. Food and Drug Administration regulates dietary supplements as a food, not as a drug. As health care providers, we must be aware of current trends in supplements and nutrition programs so that we can screen our patients for contraindications to aesthetic treatments and educate and promote specific supplements/programs that are safe and evidence-based. Oxidative stress, chronic inflammation, and increased glycation can accelerate the aging process. The combination of an anti-inflammatory diet and pharmaceutical-grade nutritional supplements can impact the multiple forces involved in skin aging and help balance skin homeostasis. Using specific nutritional interventions and supplements can help repair damaged skin, improve skin health, and reduce skin senescence. Aesthetic providers can enhance healing and clinical results by educating patients and providing high-quality supplements that promote good aesthetic outcomes.