Calcium hydroxylapatite microspheres activate fibroblasts through direct contact to stimulate neocollagenesis

Decoding the Implications of Glucagon-like Peptide-1 Receptor Agonists on Accelerated Facial and Skin Aging

Following the advent of glucagon-like peptide-1 receptor agonists (GLP-1RAs), subsequent unintended effects such as accelerated facial aging and altered skin health have been noted. This review delves deeper into the causative underlying mechanisms and provides insights into the intricate relationship between GLP-1RAs, adipose tissue, and premature facial aging, thereby highlighting the need for a nuanced understanding of their effects on facial alterations and skin health. Studies exploring the potential effects of GLP-1RAs on facial alterations and offering insights into the possible underlying mechanisms, causes, and clinical implications were included. The accelerated facial aging and altered skin health observed in GLP-1RA patients appears to be multifactorial, involving loss of dermal and subcutaneous white adipose tissue, and altered proliferation and differentiation of adipose-derived stem cells (ADSCs), and impacts on the production and secretion of hormonal and metabolic factors. These changes compromise the structural integrity and barrier function of the skin and may lead to diminished facial muscle mass, further exacerbating the appearance of aging. The insights presented call for a paradigm shift in the clinical management of facial changes induced by GLP-1RAs, with a focus on treatment strategies aimed at targeting ADSC stimulation. These include autologous fat transfers to reintroduce cells rich in ADSCs for rejuvenation, composite fat grafting combining autologous fat with/without stromal vascular fraction, and the strategic use of soft tissue fillers for volume restoration and biostimulation. This review highlights the potential role of GLP-1RAs in modulating adipose tissue dynamics, thereby contributing to accelerated aging through metabolic, structural, and hormonal pathways.

LEVEL OF EVIDENCE: 5

Pilot Study: Single-depth Superficial Ultrasound with Subdermal Injections of Diluted Calcium Hydroxylapatite for Improving Lower Face Skin Quality

Background

The lower face can be challenging to treat. We assessed the effectiveness of combining single-depth superficial microfocused ultrasound with visualization (MFU-V, Ultherapy; Merz North America, Inc. Raleigh, N.C.) and subdermal injections of diluted calcium hydroxylapatite (CaHA, Radiesse; Merz North America, Inc. Raleigh, N.C.) in a single session for improving skin quality in the lower face.

Methods

This study enrolled women with moderate-to-severe fine lines and skin unevenness on the lower face who desired nonsurgical intervention. Single-depth MFU-V treatment (10 MHz/1.5 mm) was followed by subdermal injections of diluted (1:1) CaHA. Subjects were followed up for 24 weeks posttreatment. Objective skin quality assessments (Rv: wrinkle depth; R3z: skin unevenness) were performed using LifeViz Micro (QuantifiCare, Sophia Antipolis, France). Subjective assessments included the modified Fitzpatrick Wrinkle Scale visual analog scale, Global Aesthetic Improvement Scale, and global satisfaction scale.

Results

Twelve subjects completed the study. The mean Rv value, mean R3z value, and mean modified Fitzpatrick Wrinkle Scale visual analog scale score improved significantly from baseline to week 24 (mean differences: -0.0321 mm, -0.0684 mm, -1.1667; all P < 0.001). All subjects were rated by the investigators as having demonstrated improvement in their overall aesthetic appearance as early as week 4. All subjects were "very satisfied" or "satisfied" with their treatment from week 12 onwards. No unexpected adverse events were reported.

Conclusions

Combination treatment with single-depth superficial MFU-V and diluted CaHA in a single session significantly improved lower facial skin quality, as assessed by both objective and subjective outcome measures.

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.

Optimized Calcium Hydroxylapatite Formulation and Its Injection Technique for Hand Rejuvenation: A Retrospective Study

INTRODUCTION

Hand rejuvenation treatment is in high demand in cosmetic medicine. Radiesse®, a commercially available formulation of calcium hydroxylapatite (CaHA), is safe, biocompatible, and provides long-lasting results.

OBJECTIVE

The study aimed to retrospectively evaluate the efficacy and safety of the presented formulation of Radiesse® and its injection procedure.

METHODS

The hands of 58 women were treated employing Radiesse® diluted with lidocaine. The treatment was performed using a blunt cannula following the proximal-to-distal fanning technique at two entry points on the dorsum of the hands. The patients received 1-4 treatments over a follow-up period of up to five years.

RESULTS

The hands of 58 females were evaluated using the Merz Hand Grading Scale (MHGS) and treated with the presented CaHA formulation. After the first treatment, 55 patients (94.8%) achieved a 1-point improvement, and 19 patients (32.8%) did not receive further treatment, being satisfied with the results. The remaining 39 women (67.2%) received 2-4 follow-up treatments. At the end of the treatment(s), 46 women (79%) achieved a final improvement of one point, and 12 women (21%) a final improvement of two points. Three minor adverse events were registered.

CONCLUSIONS

Radiesse® diluted with lidocaine is an excellent choice for hand rejuvenation. The formulation and technique proved to be safe and efficient. In our experience, a blunt cannula should be employed for optimal vein correction. The treatment was highly satisfying, although planning a second treatment during the 1-month follow-up visit is recommended to best achieve long-lasting results.

Calcium Hydroxyapatite as a Co-adjuvant Treatment Option in a Patient With Morphea: A Report of a Case With a One-Year Follow-Up

Morphea, or localized scleroderma, is a chronic inflammatory condition that unequivocally affects the dermis and subcutaneous connective tissue. It undeniably causes significant disfigurement in approximately half of patients, profoundly impacting their self-esteem. The available treatment options include corticosteroids (taken orally or administered subcutaneously), phototherapy, CO2 fractional laser treatment, and biologically mediated medications. It is crucial to note that using fillers as adjuvant therapy for inflammatory diseases indisputably raises concerns due to the potential to trigger inflammation and lead to disease reactivation. In one case, a 24-year-old patient with morphea on her face underwent a combined approach involving plastic surgery, dermatology, and regenerative aesthetics treatment with lipo-filling initially by an expert plastic surgeon. Then, after reviewing the literature and consensus from the dermatologist, aesthetics physician, and alternative medicine expert, it was decided to use calcium hydroxylapatite-carboxymethylcellulose (Radiesse, Merz Pharmaceuticals GmbH, Frankfurt, Germany) in the affected area. After a year of follow-up, there was a significant improvement in the appearance of her face and skin, as confirmed by a 10-point improvement on an activity measuring scale. Additional research will solidify whether calcium hydroxylapatite (CaHA) is the optimal injectable for treating dermal autoimmune diseases. Our initial approach demonstrates significant promise for regenerative biostimulation. Through collaboration, we have effectively integrated plastic surgery techniques, fillers, dermatologists, and alternative medicine perspectives to treat inflammatory diseases, providing a comprehensive and robust exploration of morphea treatment.

Photothermal modulation of gingival fibroblasts via polydopamine-coated zirconia: A novel approach for promoting peri-implant soft tissue integration

Achieving robust soft tissue integration around dental implants is crucial for long-term clinical success, as it forms a protective biological seal against bacterial invasion. However, the soft tissue attachment to implants is relatively deficient compared to natural teeth, particularly in the connective tissue region lacking sufficient gingival fibroblasts and collagen fiber alignment. This study proposed an innovative strategy to enhance peri‑implant soft tissue integration by modulating gingival fibroblast behavior via photothermal conversion. Zirconia surfaces were coated with polydopamine (PDA), a melanin-like polymer exhibiting near-infrared (NIR) absorption for photothermal conversion. Under NIR irradiation, the PDA coating enabled mild hyperthermia (42-43 °C) on the zirconia surface. Remarkably, this mild photothermal stimulation significantly promoted human gingival fibroblast proliferation, adhesion, and collagen production compared to unmodified zirconia in vitro. By utilizing the photothermal properties of PDA coatings to modulate cellular behaviors beneficial for connective tissue formation, this approach provides a promising avenue to achieve improved soft tissue integration and long-term stability of dental implants. The findings highlight the innovative potential of combining biomaterial surface engineering with photothermal therapy for applications in implant dentistry.

Comparative Rheology of Hyaluronic Acid Fillers, Poly-l-lactic Acid, and Varying Dilutions of Calcium Hydroxylapatite

Background

This study examines the rheological properties of various dermal fillers, including hyaluronic acid (HA) fillers, poly-L-lactic acid (PLLA), and calcium hydroxylapatite-carboxymethylcellulose (CaHA-CMC) gels, with a particular focus on the impact of aqueous dilution on CaHA-CMC's rheology and potential clinical implications.

Methods

Using standardized rheological analysis, we measured and compared the elastic modulus (G'), viscous modulus (G″), and the tan δ values of different dilutions of CaHA-CMC against published values of HA and PLLA fillers. The study aimed to determine the potential clinical use of application-specific CaHA-CMC hydrogel dilutions along a range of gel strength and cohesion for hydrogel fillers in current use.

Results

The findings demonstrate that CaHA-CMC's rheological properties can be tailored across a broad spectrum of viscoelastic parameters through titrated dilution, ranging from high elasticity to low cohesion. Varying the aqueous volume allows for the rheomodulation of CaHA-CMC, potentially matching the entire rheological spectrum of HA fillers and suggesting an expanded range of clinical applications.

Conclusions

The versatility of CaHA-CMC through dilution may offer a customizable approach for clinical applications, providing practitioners with the ability to fine-tune the properties of fillers to meet specific patient needs and treatment goals. This study lays the groundwork for the potential future use of filler dilutional rheomodulation in clinical practice, tailored to patient- and application-specific needs.

Guided SEFFI and CaHA: A Retrospective Observational Study of an Innovative Protocol for Regenerative Aesthetics

Background/Objectives: This retrospective observational study sought to determine the efficacy and safety of an innovative combined treatment protocol using guided Superficial Enhanced Fluid Fat Injection (SEFFI) and calcium hydroxylapatite (CaHA) in facial rejuvenation. Methods: A total of 158 patients (149 females and 9 males) underwent the combined treatment of guided SEFFI and diluted/hyperdiluted CaHA. The study evaluated treatment outcomes at 30, 90, and 150 days post-treatment using the Global Aesthetic Improvement Scale (GAIS) and three-dimensional photogrammetric analysis. Results: The combined treatment demonstrated consistent enhancement in skin quality and facial volume across temporal, malar, zygomatic, and jawline regions. At 90 days post-treatment, substantial improvements were observed, with the GAIS scores reflecting significant enhancements in both skin quality and volume, which were sustained or slightly improved by 150 days. Minor complications, predominantly ecchymosis at the injection sites, resolved within a week, confirming the treatments' safety. Conclusions: The integration of guided SEFFI and CaHA resulted in significant improvements in skin quality and facial volume with minimal complications. Further research is recommended to consolidate these findings and explore long-term outcomes.

A Structured Approach for Treating Calcium Hydroxylapatite Focal Accumulations

BACKGROUND

Radiesse, a widely utilized calcium hydroxylapatite (CaHA) dermal filler, has shown effectiveness in soft tissue augmentation and regeneration. As with all dermal fillers, the potential for nodules may arise. Understanding the pathogenesis of these nodules and exploring effective treatment methodologies are crucial for optimizing patient outcomes.

OBJECTIVES

A literature search was carried out to identify published literature documenting reversal of CaHA nodules. After identification, a consensus panel developed a structured approach, denoted by levels, for applying such reversal methods.

METHODS

This concise review presents an algorithmic approach to addressing CaHA focal accumulations (noninflammatory nodules) based on invasiveness, cost, and potential risks based on published literature.

RESULTS

Level 0 involves no intervention, relying on natural degradation for asymptomatic nodules. Level 1 interventions utilize mechanical dispersion techniques, including massage and in situ dispersion, which have demonstrated high success rates, cost effectiveness, and minimal invasiveness. Level 2 introduces alternative modalities such as pharmacological treatments with 5-fluorouracil and corticosteroids, lasers, and experimental approaches. Level 3 represents last-resort options, including calcium-chelating agents, manual removal, and surgical excision.

CONCLUSIONS

The article offers a structured approach to managing CaHA focal accumulations.

LEVEL OF EVIDENCE: 4

Hyperdiluting Calcium Hydroxylapatite With Platelet-Rich Plasma and Hyaluronidase for Improving Neck Laxity and Wrinkle Severity

The two cases discussed in this report investigate the efficacy and safety of a novel injectable therapy for treating neck wrinkles and skin laxity, utilizing a combination of hyperdiluted calcium hydroxylapatite (CaHA), platelet-rich plasma (PRP), and hyaluronidase. Two patients presenting with moderate neck wrinkles and laxity underwent treatment and were evaluated several months later. The combined therapy demonstrated improvements in skin texture and laxity following a single treatment. The rationale behind incorporating PRP and hyaluronidase was their potential to amplify the regenerative effects of CaHA. PRP contains growth factors that stimulate collagen production and tissue regeneration while hyaluronidase facilitates the breakdown of hyaluronic acid, promoting better diffusion and more even product dispersion. The findings from these cases provide emerging preliminary evidence supporting the safety and efficacy of this innovative combination therapy for addressing neck wrinkles and laxity. This is the first documented instance of skin priming CaHA with hyaluronidase and PRP. Future investigations are warranted to explore the application of this treatment for other anatomical regions and to delineate the role of each injected component.

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.

Development of a multifunctional nano-hydroxyapatite platform (nHEA) for advanced treatment of severely infected full-thickness skin wounds

The treatment of full-thickness skin injuries complicated by severe infection is hampered by the lack of comprehensive solutions that can regulate the various stages of wound healing. Consequently, there is an urgent need for a multifunctional dressing capable of multi-level regulation. In this study, we propose a novel solution by covalently integrating ε-poly-l-lysine-grafted gallic acid (EG) and in situ bioreduced silver nanoparticles (AgNPs) onto nano-hydroxyapatite (nHAP), thereby developing a multi-layered, multifunctional nanoplatform (nHEA). Cell experiments have shown that, compared to nHAP and nHAP loaded only with EG (nHEG), the addition of AgNPs to nHEA confers excellent antibacterial properties while maintaining optimal biocompatibility. The incorporation of EG onto nHEG and nHEA imparts antioxidation, anti-inflammatory, and pro-angiogenic functions, and the release of Ca2+ and EG further enhances fibroblast migration and collagen secretion. In a rat model of full-thickness skin injury with severe infection, nHEA demonstrates remarkable antibacterial and anti-inflammatory effects, along with promoting collagen remodeling and regeneration. Together, both cell experiments and animal studies confirm the significant potential of this innovative multifunctional nanoplatform in the treatment of full-thickness skin injuries with severe infection. STATEMENT OF SIGNIFICANCE: Treating infected full-thickness skin injuries poses a longstanding challenge due to the lack of comprehensive solutions that can regulate different stages of wound healing. This study introduces a novel multifunctional nanoplatform, nHEA, developed by covalently integrating ε-poly-l-lysine grafted with gallic acid (EG) and in situ bioreduced AgNPs onto nano-hydroxyapatite (nHAP). Cell experiments reveal that the integration of AgNPs enhances nHEA's antibacterial performance while maintaining optimal biocompatibility. The inclusion of EG bestows antioxidant, inflammation-regulating, and angiogenetic properties upon nHEA, and the release of Ca2+ and EG stimulates the migration and collagen secretion of fibroblast cells. Consequently, nHEA exhibits superior antibacterial and inflammation-regulating efficacy, and stimulates collagen remodeling and regeneration in vivo, making it a promising treatment for severely infected skin injuries.

Dilutional rheology of Radiesse: Implications for regeneration and vascular safety

BACKGROUND

Calcium hydroxylapatite-carboxymethylcellulose (CaHA-CMC) injectables have emerged as dual-purpose fillers with bioregenerative and direct filling capabilities.

AIMS

This study investigates the rheological properties of CaHA-CMC and its CMC carrier gel at various dilutions.

METHODS

The storage modulus (G'), loss modulus (G″), complex viscosity (η*), loss factor (tan δ), cohesivity, and extrusion force were evaluated for a range of CaHA-CMC aqueous dilutions with an oscillatory rheometer, drop weight testing, and force analysis, respectively.

RESULTS

Results revealed a significant decrease in G', η*, and increase in tan(δ) with increasing dilution, indicating a decline in the product's direct filling capabilities. Cohesivity decreased dramatically with dilution, potentially enhancing tissue biointegration and the product's biostimulatory effects. The CMC gel carrier displayed inelastic and non-resilient properties, with rheological changes differing from CaHA-CMC. Dilutional rheology was also correlated with previously published dilution-dependent biostimulatory data where hyperdiluted CaHA-CMC (>1:2) demonstrated a regenerative profile and diluted or hypodiluted mixtures retained meaningful filling properties and increased regeneration.

CONCLUSIONS

These findings offer a continuum for tailoring the product's rheological profile to match specific tissue requirements. Customizable rheology allows CaHA-CMC to be tuned for either filling and contouring or optimal regenerative effects. Importantly, safety implications related to vascular occlusion suggest that dilutional rheomodulation decreases the risk of vascular events. In conclusion, this study highlights the significant impact of aqueous dilution on the rheological properties of CaHA-CMC and its carrier gel. The findings support the clinical application of tailored dilutions to achieve desired outcomes, providing versatility and safety for aesthetic applications.

A morphological analysis of calcium hydroxylapatite and poly-l-lactic acid biostimulator particles

Injectable fillers, pivotal in aesthetic medicine, have evolved significantly with recent trends favoring biostimulators like calcium hydroxylapatite (CaHA-CMC; Radiesse, Merz Aesthetics, Raleigh, NC) and poly-l-lactic acid (PLLA; Sculptra Aesthetics, Galderma, Dallas, TX). This study aims to compare the particle morphology of these two injectables and examine its potential clinical implications. Utilizing advanced light and scanning electron microscopy techniques, the physical characteristics of CaHA-CMC and PLLA particles were analyzed, including shape, size, circularity, roundness, aspect ratio, and quantity of phagocytosable particles. The findings reveal several morphological contrasts: CaHA-CMC particles exhibited a smooth, homogenous, spherical morphology with diameters predominantly ranging between 20 and 45 µm, while PLLA particles varied considerably in shape and size, appearing as micro flakes ranging from 2 to 150 µm in major axis length. The circularity and roundness of CaHA-CMC particles were significantly higher compared to PLLA, indicating a more uniform shape. Aspect ratio analysis further underscored these differences, with CaHA-CMC particles showing a closer resemblance to circles, unlike the more oblong PLLA particles. Quantification of the phagocytosable content of both injectables revealed a higher percentage of phagocytosable particles in PLLA. These morphological distinctions may influence the tissue response to each treatment. CaHA-CMC's uniform, spherical particles may result in reduced inflammatory cell recruitment, whereas PLLA's heterogeneous particle morphology may evoke a more pronounced inflammatory response.

Dual Functionalization of Hyaluronan Dermal Fillers with Vitamin B3: Efficient Combination of Bio-Stimulation Properties with Hydrogel System Resilience Enhancement

Hyaluronic acid (HA) hydrogels are commonly used for facial dermal filling and for alternative medical aesthetic purposes. High diversity exists in commercial formulations, notably for the optimization of finished product stability, functionality, and performance. Polyvalent ingredients such as calcium hydroxylapatite (CaHA) or vitamin B3 (niacinamide) are notably used as bio-stimulants to improve skin quality attributes at the administration site. The aim of the present study was to perform multi-parametric characterization of two novel cross-linked dermal filler formulas (HAR-1 "Instant Refine" and HAR-3 "Maxi Lift") for elucidation of the various functional impacts of vitamin B3 incorporation. Therefore, the HAR products were firstly comparatively characterized in terms of in vitro rheology, cohesivity, injectability, and resistance to chemical or enzymatic degradation (exposition to H2O2, AAPH, hyaluronidases, or xanthine oxidase). Then, the HAR products were assessed for cytocompatibility and in vitro bio-stimulation attributes in a primary dermal fibroblast model. The results showed enhanced resilience of the cohesive HAR hydrogels as compared to JUVÉDERM® VOLBELLA® and VOLUMA® reference products in a controlled degradation assay panel. Furthermore, significant induction of total collagen synthesis in primary dermal fibroblast cultures was recorded for HAR-1 and HAR-3, denoting intrinsic bio-stimulatory effects comparable or superior to those of the Radiesse® and Sculptra™ reference products. Original results of high translational relevance were generated herein using robust and orthogonal experimental methodologies (hydrogel degradation, functional benchmarking) and study designs. Overall, the reported results confirmed the dual functionalization role of vitamin B3 in cross-linked HA dermal fillers, with a significant enhancement of hydrogel system stability attributes and the deployment of potent bio-stimulatory capacities.

Safety and Efficacy of Diluted Calcium Hydroxylapatite for the Treatment of Cellulite Dimpling on the Buttocks: Results from an Open-Label, Investigator-Initiated, Single-Center, Prospective Clinical Study

BACKGROUND

Cellulite is a condition characterized by dimpling and contour irregularities in the gluteal and thigh regions, affecting an estimated 80-98% of postpubertal women. Innovative treatments for cellulite dimpling in the buttocks have gained popularity in recent years, seeking new solutions for a historically challenging condition. In this open-label, investigator-initiated, single-center, prospective clinical study, the authors sought to evaluate the safety and efficacy of diluted calcium hydroxylapatite (CaHA; Radiesse®, Merz Aesthetics, Raleigh, NC) for the treatment of cellulite dimpling in the buttocks of adult women.

METHODS

Subjects underwent three treatment sessions, receiving a total of 12 syringes of 1:1 diluted CaHA administered using a cannula-based subcision technique. Endpoints included the cellulite severity scale (CSS), the global aesthetic improvement scale (GAIS), subject satisfaction measured on a 5-point scale, and three-dimensional imaging analysis via the Quantificare 3D Track®.

RESULTS

Twenty-four subjects completed the study (mean age, 35 years; mean BMI, 26.88 kg/m2; mean body fat percentage, 31.29%), and no serious complications were reported. Quantitative analysis at week 14 revealed a mean reduction of 54.0% in the number of visible dimples and 50.09% in dimple depth compared to baseline. The mean CSS score decreased by 4.29 points, representing a 43.92% improvement in cellulite severity from baseline (p < 0.0001). Both physician-assessed and subject-assessed GAIS ratings also demonstrated significant improvement, with 91.6% of subjects rating their cellulite appearance as "improved" or greater.

CONCLUSION

The results of this study support the safety and efficacy of diluted CaHA for treating cellulite dimpling in adult women.

LEVEL OF EVIDENCE II

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 .

CLINICAL TRIALS REGISTRATION

This study is registered with clinicaltrials.gov (ID: NCT05885035) and can be found at this link: https://clinicaltrials.gov/study/NCT05885035 .

Hyperdilute Calcium Hydroxylapatite for the Treatment of Perioral Rhytids: A Pilot Study

Background

The perioral region plays a crucial role in facial aesthetics and is susceptible to age-related changes, such as wrinkles and fine lines due to its dynamic nature. Type I collagen is crucial in providing structural integrity and resilience to the skin. Calcium hydroxylapatite (CaHA-CMC) is a widely used dermal filler whose particles stimulate fibroblastic responses within the skin. When diluted, CaHA-CMC has emerged as a useful treatment for collagen stimulation.

Objectives

The objective of the study is to evaluate the efficacy and safety of hyperdilute CaHA-CMC at a 1:3 ratio, specifically administered in the perioral area, to assess its impact on deep rhytids and overall skin quality.

Methods

Females aged 40 to 70 years with moderate-to-severe wrinkles in the perioral region based on a validated wrinkle scale were injected with hyperdilute CaHA-CMC throughout the perioral region at 2 separate injection intervals (Weeks 1 and 8). This was followed by an injection of hyaluronic acid (CPM-HA22.5) into the perioral region at Week 16. The primary endpoint was a ≥1-point improvement from baseline on the wrinkle grading scale.

Results

Twelve female participants were treated. Investigator and patient ratings based on the 5-point Merz perioral/lip wrinkle grading scale showed at least 1 grade improvement in 83% of the patients with a P-value of .0156. A majority of both investigators and patients rated their lip wrinkles as improved in appearance compared with their baseline.

Conclusions

Hyperdilute CaHa-CMC at a 1:3 dilution may be a safe and effective treatment for improving the depth and overall appearance of perioral rhytids.

Level of Evidence 4

A systematic review of Radiesse/calcium hydroxylapatite and carboxymethylcellulose: evidence and recommendations for treatment of the face

Radiesse® is a filler composed of calcium hydroxylapatite microspheres suspended in a carboxymethylcellulose gel (CaHA/CMC). It has robust rheological properties that have been associated with its versatility. CaHA/CMC is employed for both on-label indications of filling wrinkles or lines, volumizing, and contouring of areas as well as off-label indications aiming at biostimulation and skin tightening. However, despite the expanding use of CaHA/CMC, overall evidence and recommendations for treatment are currently lacking. This paper aims to provide an up-to-date overview of CaHA/CMC clinical applications, together with a level of evidence of supporting literature, focusing on the face. Based on the data, CaHA/CMC may be considered a safe and effective treatment option for cheeks, jawline, HIV-related facial lipoatrophy, and nasolabial folds. Treatment of marionette lines, chin, pre-jowl, and corner of the mouth also tends to respond with a high degree of efficacy. Despite the recent trend, guidelines, and safety profile of diluted and hyperdiluted Radiesse® , no randomized controlled trials have been published.

Biostimulating fillers and induction of inflammatory pathways: A preclinical investigation of macrophage response to calcium hydroxylapatite and poly-L lactic acid

INTRODUCTION

Initial macrophage response to biostimulatory substances is key in determining the subsequent behavior of fibroblasts and the organization of newly synthesized collagen. Though histological studies suggest that calcium hydroxylapatite (CaHA) filler initiates a regenerative healing response with collagen and elastin deposition similar to natural, healthy tissue rather than an inflammatory response with fibrosis, the relative activity of macrophages stimulated by CaHA, as well as how this activity compares to that induced by other biostimulatory fillers, has not been explored. The aim of the study is to characterize the in vitro macrophage response to two biostimulory fillers, CaHA and PLLA (poly-L lactic acid), and to evaluate their inflammatory potential.

METHODS

Primary human macrophages were incubated with two dilutions (1:50 and 1:100) of commercially available CaHA or PLLA. After 24 h incubation, an inflammation array was used to screen for the expression of 40 cytokines, released by macrophages. ELISA was used to confirm array results.

RESULTS

Four cytokines were significantly upregulated in M1 macrophages incubated with PLLA compared to both unstimulated controls and CaHA: CCL1 (p < 0.001), TNFRII (p < 0.01), MIP-1α (p < 0.05), and IL-8 (p < 0.001). In M2 macrophages, MIP-1α (p < 0.01) and MIP-1β (p < 0.01) were significantly upregulated by PLLA compared to CaHA and unstimulated controls.

CONCLUSION

Together, these findings indicate that the CaHA mode of action is a non-inflammatory response while PLLA initiates expression of several cytokines known to play a role in inflammation. Our study supports the concept that these two "biostimulatory" fillers follow distinct pathways and should be considered individually with regard to mechanism of action.

Starting Point for Protocols on the Use of Hyperdiluted Calcium Hydroxylapatite (Radiesse®) for Optimizing Age-Related Biostimulation and Rejuvenation of Face, Neck, Décolletage and Hands: A Case Series Report

Radiesse® is a dermal filler made of calcium hydroxylapatite, a natural component of the human body, which, in diluted and hyperdiluted forms, promotes, unlike other fillers, neocollagenesis, neoelastinogenesis, fibroblast proliferation, and angiogenesis, leading to a long-term improved skin quality, elasticity, tightening, and firmness. This case series examined the use of Radiesse® (Merz, Frankfurt, Germany) for skin rejuvenation and regeneration through a long-lasting action of collagen biostimulation. The report explored for the first time the use of different dilution ratios of Radiesse® in 50 patients of varying ages and skin needs. By combining microboluses, tunneling, and/or fanning techniques, Radiesse® was superficially injected in different body regions, including the full-face, neck, décolletage, and hands. The treatment was effective in improving skin thickness, laxity, and wrinkles in 95% of 30-40 year-olds, 80% of 40-60 year-olds, and 70% of >60 year-olds, with an average improvement of 81.6% for the general population. The treatment was well-tolerated with no significant adverse effects reported. The report also describes specific cases and includes pictures comparing the baseline condition to the changes obtained after different months and Radiesse® sessions. The patients reported a clear improvement in skin firmness and brightness, as well as a visible improvement in wrinkles' appearance. This report found that diluting and hyperdiluting Radiesse® with flexible dilution ratios favoured a treatment's individualization, providing improved skin quality, elasticity, tightening, and firmness, without volume augmentation. In conclusion, it highlights the versatility and flexibility of Radiesse® and emphasizes its efficacy and safety in skin rejuvenation and regeneration.

Buttocks Beautification 3D with Calcium Hydroxylapatite (RadiesseTM): An Individualized Approach to Diagnosing and Treating Contour, Sagging, and Cellulite of the Buttocks in Seven Cases

Background

The demand for body procedures is increasing, and buttocks beautification is one of the most sought-after procedures in dermatological and plastic surgery clinics. Several aspects affect the beauty of this area, including sagging, cellulite, contour irregularity, and volume reduction. This makes treatment of the area more challenging. Calcium hydroxylapatite (CaHA), which may be injected into the buttocks, stimulates local neocollagenesis, provides volume replacement, increases the strength and elasticity of the dermis, and thickens the underlying superficial fascia. However, no protocol for buttocks beautification tailors the dilution and deep application of CaHA filler simultaneously according to clinical assessments and personal priorities regarding contour, sagging, and cellulite.

Purpose

To report the results of a minimally invasive protocol using different dilutions of CaHA (Buttocks Beautification 3D) in the buttocks with application in different planes. The treatment was performed according to a previous individualized evaluation to improve the area aesthetically.

Patients and methods

Six women and one man were submitted to the protocol. An assessment was performed to determine the shape, sagging, cellulite (in women), and patients' preferences for buttocks beautification. The dilution, volume, depth, and injection technique for CaHA were based on these assessments. The results of the treatment were then assessed using standardized photographs and patient satisfaction.

Results

We reported favorable results in six women and one man with different grades of sagging, female cellulite, and shapes of the gluteal region who were treated with CaHA injections according to a tailored protocol. All participants reported high satisfaction with the procedure.

Conclusion

Highly satisfactory results were achieved in seven adult patients who were assessed and treated for the buttocks with CaHA using an individualized protocol. Prospective studies should be performed to corroborate our findings and optimize the use of Buttocks Beautification 3D as a reliable modality of treatment for this body area.

The Role of Calcium Hydroxylapatite (Radiesse) as a Regenerative Aesthetic Treatment: A Narrative Review

For decades, a wide variety of natural and synthetic materials have been used to augment human tissue to improve aesthetic outcomes. Dermal fillers are some of the most widely used aesthetic treatments throughout the body. Initially, the primary function of dermal fillers was to restore depleted volume. As biomaterial research has advanced, however, a variety of biostimulatory fillers have become staples in aesthetic medicine. Such fillers often contain a carrying vehicle and a biostimulatory material that induces de novo synthesis of major structural components of the extracellular matrix. One such filler, Radiesse (Merz Aesthetics, Raleigh, NC), is composed of calcium hydroxylapatite microspheres suspended in a carboxymethylcellulose gel. In addition to immediate volumization, Radiesse treatment results in increases of collagen, elastin, vasculature, proteoglycans, and fibroblast populations via a cell-biomaterial-mediated interaction. When injected, Radiesse acts as a cell scaffold and clinically manifests as immediate restoration of depleted volume, improvements in skin quality and appearance, and regeneration of endogenous extracellular matrices. This narrative review contextualizes Radiesse as a regenerative aesthetic treatment, summarizes its unique use cases, reviews its rheological, material, and regenerative properties, and hypothesizes future combination treatments in the age of regenerative aesthetics.

LEVEL OF EVIDENCE: 5