121,962 research outputs found
Calcium hydroxylapatite treatment of human skin: evidence of collagen turnover through picrosirius red staining and circularly polarized microscopy
No full textNicola Zerbinati,1 Alberto Calligaro2 1Department of Surgical and Morphological Sciences, University of Insubria (Varese) and Polyspecialist Medical Center, Pavia, 2Department of Public Health, Experimental and Forensic Medicine, Unit of Histology and Embryology, University of Pavia, Pavia, Italy Background: Calcium hydroxylapatite (CaHA, Radiesse®) is a biocompatible, injectable filler for facial soft-tissue augmentation that provides volume to tissues, followed by a process of neocollagenesis for improved skin quality. Objective: To examine the effects of CaHA treatment on the molecular organization of collagen using a combination of picrosirius red staining and circularly polarized light microscopy.Methods: Five subjects received subdermal injection of 0.3 mL of CaHA in tissues scheduled for removal during abdominoplasty 2 months later. Tissue specimens from the CaHA injection site and a control untreated area were obtained from excised skin at the time of surgery. Processed tissue sections were stained with picrosirius red solution 0.1% and visualized under circularly polarized light microscopy for identification of thick mature (type I) and thin newly formed (type III) collagen fibers. Pixel signals from both the control and CaHA-treated areas were extracted from the images, and morphometric computerized hue analysis was performed to provide a quantitative evaluation of mature and newly formed collagen fibers.Results: Under picrosirius red staining and circularly polarized light microscopy, green/yellow areas (thin newly formed collagen type III) were visible among the collagen fibers in tissue sections from the area of CaHA injection. In contrast, the majority of the collagen fibers appeared red (thick mature collagen type I) in control tissues. Morphometric analysis confirmed that, following CaHA treatment, the proportion of fibers represented by thin newly formed collagen type III increased significantly (p<0.01) in comparison with the proportion of thick mature collagen type I fibers. In contrast, collagen content of control tissues consisted almost exclusively of thick mature collagen type I fibers. Conclusion: The use of picrosirius red staining and circularly polarized light microscopy provides evidence that subdermal injection of CaHA stimulates the formation of new collagen and dermal remodeling. Keywords: calcium hydroxylapatite, neocollagenesis, picrosirius red, circularly polarized light microscopy, Radiesse 
Long-term Stability and Hyaluronic Acid Filler Selection for Forehead Contouring
No full text: Hyaluronic acid (HA) fillers have progressed from superficial wrinkle correction to tools for deep 3-dimensional facial remodeling. The forehead, once addressed exclusively through surgical procedures or botulinum toxin, can now be effectively reshaped using HA fillers. This retrospective study evaluates the long-term outcomes of forehead contouring in 38 patients (36 males, 2 females; mean age: 47.6 y) treated between January 2021 and January 2024 using a low G' (20 Pa), monophasic cross-linked HA filler. Injections were performed perpendicularly to the frontal bone, targeting the space just above the periosteum to correct frontal bossing and restore contour. The mean volume used was 16 mL per patient. No major or minor complications occurred, and patient satisfaction, measured through Visual Analog Scale (VAS), averaged 91 at 12 months. Follow-up up to 36 months demonstrated stable aesthetic results, with no evidence of filler resorption, nodules, or irregularities. The use of a low-cohesivity, low-elasticity filler allowed for precise molding and excellent integration without visible distortion, even in the thin tissue planes of the forehead. Despite the absence of a filler specifically designed for this region, this approach proved effective, cost-efficient, and safe. These findings suggest that deep HA filler injections may offer a reliable, reversible, and long-lasting alternative to surgical forehead contouring. Further randomized, controlled trials are needed to define the ideal rheological parameters for forehead applications
Chemical Characterization of Hydrogels Crosslinked with Polyethylene Glycol for Soft Tissue Augmentation
No full textBACKGROUND: Hyaluronic acid (HA) based hydrogels for esthetic applications found widespread use. HA should be crosslinked for this application to achieve the correct viscoelastic properties and avoid fast degradation by the hyaluronidase enzyme naturally present in the skin: these properties are controlled by the amount of crosslinker and the fraction that is effectively crosslinked (i.e. that binds two HA chains).
AIM: Crosslinking by polyethylene glycol diglycidyl ether (PEGDE) has been more recently introduced and showed attractive features in terms of viscoelastic properties and reduced biodegradation. Aim of this paper is to define a method for the determination of the crosslinking properties of these recently introduced fillers, method that is lacking at the moment.
MATERIAL AND METHOD: The percentage of crosslinker and the fraction that is effectively crosslinked were determined by proton Nuclear Magnetic Resonance (1H NMR) and by 13C NMR, respectively. The filler were preliminarily washed with acetonitrile to remove residual PEG and then digested by hyaluronidase to obtain a sample that can be analysed by NMR.
RESULTS: The crosslinking parameters were determined in four samples of NEAUVIA PEG-crosslinked dermal fillers (produced by MatexLab S.p.A., Italy). The percentage of crosslinker was between 2.8% and 6.2% of HA, whereas the effective crosslinker ratios were between 0.07 and 0.16 (ratio between the moles of effectively crosslinked PEG and total moles of PEG). Moreover, a digestion procedure alternative to enzymatic digestion, based on acidic hydrolysis, was successfully tested for the determination of crosslinker percentage.
CONCLUSIONS: The proposed method successfully determined the two crosslinking parameters in PEG-crosslinked dermal fillers. The estimated percentage of crosslinker is similar to previously reported data for other crosslinkers, whereas the effective crosslinker ratio is lower for PEG crosslinked hydrogels
The influence of social media on patients’ perception of aesthetic treatment outcome. Satisfaction with tattoo removal: A model
No full textThe level of patient satisfaction following tattoo removal often varies and frequently diverge from clinical objectivity. This study assesses how much social media can influence patient satisfaction after picosecond laser (PSL) tattoo removal, in light of the growing influence they have on consumers. Twenty-seven patients were treated with PSL for removal of professional black tattoo. Two groups of patients were identified: those who were already being treated at our institute or had been referred by other physicians (group 1) and those who found us through social media (group 2). Clinical improvement was evaluated 8 weeks after the final laser session and patients’ satisfaction was assessed. In both groups, clinical results were homogeneous; however, Group 2 patients’ subjective Global Aesthetic Improvement Scale scores were lower than those reported by clinicians (p=0.035), while Group 1 was globally more satisfied (p<0.001). We can affirm that the influence of social media on the perceptions and expectations of patients can affect their level of satisfaction. Particularly for people who are influenced by social media, it is essential to provide explanations prior to laser treatments, in order to clarify what may actually be expected from laser sources
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