Hydroxyapatite, a natural mineral carefully composed of hydroxyl groups and calcium phosphate, has shown its unique appeal in the field of medical aesthetics. Its molecular formula, Ca10(PO4)6(OH)2, is very similar to the mineral composition of bone, which allows it to achieve a close chemical bonding with human tissue. Not only that, hydroxyapatite has a certain solubility in the body and can release ions that are harmless to the body and actively participate in the body's metabolism, providing stimulation or induction of bone growth. Due to its good biocompatibility and safety, hydroxyapatite has become an indispensable and important material for an increasingly wide range of applications in the field of medical fillers.

　　In addition, hydroxyapatite has a long history of clinical use in medical aesthetics. Since its first application in the field of medical aesthetics in 1995, it has won the favor of plastic surgeons for its excellent filling effect and ability to stimulate collagen regeneration. Subsequently, hydroxyapatite has successively gained CE certification and FDA approval, and the indications have been expanding, from dermis and subdermal soft tissue rejuvenation treatment to facial wrinkle treatment, to jawline contouring, etc., all of which have achieved remarkable results.

　　In recent years, the similarity of hydroxyapatite to the mineral portion of complex mammalian tissues has been further confirmed with the in-depth development of several clinical studies. This makes it more widely used in the field of facial filler injections, not only can effectively improve skin laxity, but also tighten the skin, and become the market just need products, market share followed by hyaluronic acid.

　　Hydroxyapatite, a unique and renewable material, is a key component of human bone. It is not only immunogen-free, but also has excellent bioactivity and biocompatibility. When placed in the body, hydroxyapatite does not induce inflammatory or foreign body reactions, ensuring its safe and effective use. In addition, its biodegradability, renewability and long-lasting plasticity make hydroxyapatite more and more widely used in the field of medical aesthetics.

　　In the human body, hydroxyapatite porous microspheres form a scaffold that promotes the production of collagen fibers by fibroblasts, thus maintaining the filler effect for more than 2 years. As the porous microspheres degrade, calcium ions and phosphates are gradually absorbed by the body, realizing the biodegradability of the material. At the same time, the porous structure of hydroxyapatite provides an ideal environment for cell adhesion and proliferation, contributing to the secretion and deposition of extracellular matrix, further enhancing its regenerative capacity.

　　Compared to the possible displacement of the cavity formed by hyaluronic acid injection alone, the hydroxyapatite porous microspheres induce collagen regeneration, allowing the cavity to shrink and fill in situ effectively, thus avoiding the displacement phenomenon. In addition, the porous microspheres can reduce the swelling rate of hyaluronic acid and increase its densification, thus demonstrating superior anti-degradation and in vivo retention time.

　　In summary, hydroxyapatite, as a highly effective regenerative material, has demonstrated its unique advantages in the field of medical aesthetics. Its ability to stimulate collagen regeneration, high energy and long-lasting stability, as well as excellent filling, contouring and regeneration effects make hydroxyapatite an indispensable and important choice in the field of medical aesthetic fillers.

　　02

　　Adsorption of proteins for tissue repair

　　Hydroxyapatite (CaHA) is slightly soluble in water and exhibits a strong ion exchange capacity. This ability allows it to effectively adsorb proteins and a variety of growth factors, thereby creating localized areas of autologous growth factor enrichment. This property further facilitates the process of tissue repair and regeneration.

　　03

　　Enhance skin quality for long-lasting protection

　　Hydroxyapatite (CaHA) is milky white in color and shows a brightening effect immediately after filling. In the presence of body fluids, the Ca2+ produced by its decomposition enters the calcium reservoir, thereby increasing the rate of renewal of the stratum corneum and enhancing the lipid synthesis of keratinized cells. This material also has excellent water retention properties and effectively forms a protective skin barrier, leading to long-term improvements in skin quality.

　　04

　　Overview of hydroxyapatite products worldwide

　　Hydroxyapatite, a popular ingredient in the field of medical aesthetics, has been widely used worldwide. Overseas brands such as Radiesse and HArmonyCA, as well as domestic brands such as Yueling Sculpture, Filipinopril, and HaiMiYunJing, all use hydroxyapatite microspheres as the core ingredient to achieve facial contouring and skin quality improvement through injection. These products have not only inherited the excellent properties of hydroxyapatite, but have also been finely divided for different applicable areas and effects, such as deep filling, medium and deep replenishment, and superficial skin quality improvement, in order to meet the diversified needs of consumers.

　　05

　　Hydroxyapatite: Cross-field application from orthopedics to medical aesthetics

　　❖ Applications in the field of orthopedics

　　Bone Repair and Replacement: Hydroxyapatite, as the main component of human bones and teeth, has become an ideal bone repair and replacement material with its excellent biocompatibility and osteoconductivity. Its extensive use is evident in orthopedic surgeries such as filling bone defects, repairing fractures or implanting artificial joints. By forming a chemical bond with the surrounding bone tissue, hydroxyapatite can effectively promote the growth and differentiation of bone cells, accelerating the repair and regeneration of bone tissue.

　　Osteoporosis treatment: Another major application of hydroxyapatite is the treatment of osteoporosis. It not only promotes bone formation and increases bone density, but also effectively inhibits bone resorption, providing patients with comprehensive treatment. By enhancing the mechanical strength of bone tissue, this material plays a key role in the prevention and treatment of osteoporosis.

　　❖ Applications in the medical aesthetic field

　　Facial Filling and Shaping: With the rapid development of medical aesthetic technology, hydroxyapatite has gradually entered the medical aesthetic field with its good biocompatibility and degradability. In facial aesthetics, it is used as a filler to improve facial contour, smooth wrinkles and depressions through injection, and achieve natural facial contouring and rejuvenation effects. Its ability to stimulate collagen regeneration and extracellular matrix reconstruction makes this effect even more remarkable.

　　Anti-Aging and Skin Firming: In addition, hydroxyapatite has shown excellent results in anti-aging and skin firming. Through mechanotransduction and induced collagen regeneration, it effectively improves skin laxity, improves skin elasticity, and reduces the formation of wrinkles. Medical products containing hydroxyapatite on the market have further enhanced their bioactivity and cosmetic effects by incorporating new materials such as calcium phosphate complex.

　　❖ Evolution of the scope of application

　　The leap from orthopedics to medical aesthetics: the application of hydroxyapatite in the field of orthopedics has laid a solid foundation for its expansion in the field of medical aesthetics. With the growing demand for cosmetic anti-aging and the continuous innovation of medical aesthetic technology, this material is gradually extended from the orthopedic field to the medical aesthetic field.

　　Technological innovation: In the process of application in the field of medical aesthetics, hydroxyapatite has experienced technological innovation from single material to composite material, from basic filling to multi-functional beauty. These advances have not only improved the cosmetic effect and safety of hydroxyapatite, but also opened up a broader market prospect for it.

　　Prospect: Looking ahead, the application of hydroxyapatite in the field of medical aesthetics is expected to continue to expand and deepen. With the continuous advancement of scientific research and technological innovation, it is believed that this material will bring more innovative cosmetic experiences and therapeutic effects.

　　Market demand: With the growing concern for health and beauty, the application of hydroxyapatite in the field of medical aesthetics is becoming more and more promising. In particular, hydroxyapatite shows great potential in anti-aging, skin tightening and facial contouring.

　　Research Direction: In the future, hydroxyapatite research will be more focused on improving the bioactivity, degradability and safety of the material. With advances in biotechnology and nanotechnology, hydroxyapatite is expected to be fused with other biomaterials to develop more advanced and efficient medical aesthetic products.

　　Currently, regarding the formulation and preparation of the regenerative material hydroxyapatite, researchers are continuously exploring and optimizing. In terms of formulation, the proportion of calcium and phosphorus sources as well as other additives can be flexibly adjusted according to actual needs. During the preparation process, the reaction conditions, such as temperature, stirring speed and pH, need to be strictly controlled to ensure that hydroxyapatite can be generated purely and efficiently. After a series of steps such as reaction, aging, filtration, washing, drying and grinding, the desired hydroxyapatite powder is finally obtained for further application in the field of medical aesthetics.

　　It should be emphasized that the above mentioned formulations and processes are intended as examples only and are not applicable to all hydroxyapatite preparation situations. In actual operation, the preparers need to flexibly adjust and optimize the process according to the specific product requirements, existing preparation conditions and equipment conditions and other factors.

　　Meanwhile, with the continuous progress of science and technology, more and more innovative preparation techniques and formulations have been developed. For example, some research teams have adopted hydrothermal, sol-gel or microwave-assisted synthesis methods to prepare hydroxyapatite, which not only have milder reaction conditions, but also produce products with higher purity and more controllable crystalline form. Therefore, when selecting the formulation and preparation route of hydroxyapatite, various factors should be considered comprehensively and the latest scientific progress should be taken into account.