Arch Aesthetic Plast Surg.  2019 Oct;25(4):147-153. 10.14730/aaps.2019.01739.

Safety and efficacy of polycaprolactone copolymer nanosphere hydrogel injected into the scalp dermal tissue of rats

Affiliations
  • 1Department of Plastic and Reconstructive Surgery, Hallym University College of Medicine, Seoul, Korea. c21ps@hanmail.net
  • 2Rose Plastic Surgery Clinic and Rose Lab, Seoul, Korea.

Abstract

BACKGROUND
Currently, dermal fillers need to be 25 µm or larger to reduce in vivo degradation by macrophages. However, the large size of fillers may cause side effects, including interruption of blood flow and nodule formation. Therefore, using rats, we tested a polycaprolactone copolymer hydrogel with nanoscale particles that could maintain a low in vivo degradation rate.
METHODS
Thirty-six 6-week-old Sprague-Dawley rats were divided into group A (normal saline), group B (polycaprolactone microsphere filler), and group C (polycaprolactone copolymer nanosphere hydrogel). The corresponding materials were injected into the dermal layer of the scalp of the rats. At 4, 8, and 12 weeks after injection, blood biochemical and kidney and liver histological analyses were performed. Tissues were examined using hematoxylin-eosin staining to observe tissue infiltration of materials. Collagen formation in the dermal tissue of the scalp was observed with Masson trichrome staining and the collagen content was quantified using a soluble collagen assay kit.
RESULTS
The histologic examination for organ infiltration showed no abnormal findings. All blood test results were within the normal ranges. The amount of collagen at 12 weeks increased by 1.22 mg/g in group C and by 0.6 mg/g in group B.
CONCLUSIONS
The results reveal that the nanosphere complex near the injection site induced collagen formation. Regardless of the sphere size, aggregation of the copolymer prevented macrophage phagocytosis. The polycaprolactone copolymer nanosphere hydrogel was effective for more than 3 months when injected in the scalp dermal tissue of Sprague-Dawley rats and can be used safely.

Keyword

Polycaprolactone; Nanosphere; Dermal fillers

MeSH Terms

Animals
Collagen
Dermal Fillers
Hematologic Tests
Hydrogel*
Kidney
Liver
Macrophages
Microspheres
Nanospheres*
Phagocytosis
Rats*
Rats, Sprague-Dawley
Reference Values
Scalp*
Collagen
Dermal Fillers
Hydrogel
Full Text Links
  • AAPS
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2024 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr