ABSTRACT
BACKGROUND: Poly L-lactic acid (PLLA) can stimulate fibrous tissue regeneration to exert a filling effect. However, severe inflammatory reactions and unsatisfactory effects remain a concern. OBJECTIVE: Herein, we describe the mechanism of action, efficacy, and safety of PLLA microspheres in suspension (PLLA-b-PEG/HA) for facial contouring and soft tissue augmentation. METHODS: PLLA-b-PEG/HA, ssynthesized by copolymerization with ethylene glycol, were suspended in hyaluronic acid (HA). Physiological verification was performed using scanning electron microscopy and X-ray computed tomography. PLLA-b-PEG/HA were subcutaneously injected into the dorsal region of 4-month-old rabbits. Ultrasound assessed volumetric capacity at 3 days and 1, 2, 4, and 12 weeks. The inflammatory response, collagen production, and HA degradation were evaluated. A retrospective case series of 10 patients who received PLLA-b-PEG/HA injections was conducted to assess long-term efficacy and safety. RESULTS: PLLA-b-PEG exhibited a spherical structure with a smooth surface (20-45 µm diameter). In rabbits, implant site volume increased within 4 weeks, gradually decreasing thereafter. Fibrous capsules, microvessel density, and new collagen fiber formation progressively increased at 4, 12, and 26 weeks after injection. Clinical data demonstrated significant improvements in face contouring at months 3 and 12 after injection. All patients showed improved internal contours based on the Global Aesthetic Improvement Scale. After 12 months, 90% of the patients retained good shaping and support effects with minimal adverse reactions. CONCLUSIONS: PLLA-b-PEG/HA demonstrated superior biocompatibility and facial regeneration potential, with outstanding dual collagen-stimulating properties. The clinical efficacy and safety of PLLA-b-PEG/HA have been validated and established as a promising therapeutic option.
ABSTRACT
Objective:To prepare human decellular adipose tissue matrix (DAT) as injectable homogenate by a specially developed high-speed soft tissue homogenizer with controllable temperature, and to investigate its cellular compatibility and filling effect.Methods:From March 2019 to March 2021, DAT was obtained in the 940th Hospital from normal adipose tissue after decellular treatment. The DAT was mixed with normal saline at the rate of 1: 12. The specially developed high-speed soft tissue homogenizer with controllable temperature was used to conduct homogenization at 803×g for 10 min. The produced DAT homogenizer could pass through the 27G needle smoothly. DAT homogenate was observed under scanning electron microscope and its cytocompatibility was detected. Finally, granular fat, DAT homogenate and DAT homogenate + ADSCs were injected into the back of rats respectively, and the filling effect, angiogenesis ability and inflammatory infiltration were compared.Results:After decellular treatment, adipose tissue changed into DAT without cellular residue. The particle size of DAT homogenate was about (749.91±136.79) nm, which was prepared by the specially developed temperature controlled high-speed soft tissue homogenater. The adhesion rate was (92.16±1.00) %, and the A value increased with time. The cell growth was good, and the homogenate had no toxicity to the cells. In vivo experiment, the filling effect of DAT homogenate and DAT homogenate + ADSCs was significantly better than that of granulated fat group ( P<0.01). In the granulated fat group, a large number of adipocytes were necrotic and fused to form oil sacs, while DAT homogenate, DAT homogenate + ADSCs showed no obvious degradation, and some adipocytes were generated. The results of CD31 staining indicated that the number of microvessels in DAT homogenate group and DAT homogenate + ADSCs group was higher than that in granulated fat group ( P<0.01). The results of CD68 staining indicated that the inflammatory infiltration in DAT homogenate group and DAT homogenate + ADSCs group was lower than that in granule fat group ( P<0.01). Conclusions:Using the self-developed temperature controlled high-speed soft tissue homogenate device, DAT could be prepared into DAT homogenate that can pass through 27G needle. It has good biocompatibility and filling advantages, and injective process is simple, and the trauma is small, and so it could be used as filling material.
ABSTRACT
In this study, we fabricated multifunctionalized hydrogel scaffolds based on hyaluronic acid (HA)-tyrosine and human-like collagen (HLC) by crosslinking with 1, 4-butanedioldiglycidyl ether (BDDE) for soft tissue fillers. The physicochemical of HA-tyrosine/BDDE (HTB) and various proportions of HA-tyrosine/BDDE/HLC (HTBH) hydrogels were characterized by swelling ratio, mechanical strength, morphology and thermal stability. The results demonstrated various HTBH hydrogels had superior performance in mechanical properties than HTB hydrogels. The biodegradation in vitro results demonstrated the degradation of HTBH hydrogels were slower than HTB hydrogels, and residual masses of HTBH hydrogels varied with different proportions of HA-tyrosine and HLC in the presence of the combination of HAse/collagenase I. The cell counting kit-8 (CCK-8), Hoechst/PI staining and cell adhesion of various HTBH hydrogels showed less cytotoxic and superior fibroblast attachment than those of HTB hydrogels. Moreover, subcutaneous injections of HTBH hydrogels containing high proportions of HLC in mice and rabbits all exhibit better biocompatibility and anti-biodegradation compared to HTB hydrogels after 1, 4, 8, 12 and 16â¯weeks. Hematoxylin-eosin staining (H&E), immunohistochemical and transmission electron microscope (TEM) analysis results indicated HTBH hydrogels had less intense inflammatory responses with increase proportion of HLC. Taken together, HTBH hydrogels had great potential application as ideal soft tissue fillers with excellent mechanical properties, biological stability and biocompatibility.