title: Low-level laser therapy combined with platelet-rich plasma on the healing calcaneal tendon: a histological study in a rat model.
abstract: The objective of this study was to investigate the effects of low-level laser therapy (LLLT) treatment alone (λ = 660 nm and λ = 830 nm) or associated with platelet-rich plasma (PRP). We used 54 male rats divided into six groups, with nine animals each: group 1, partial tenotomy; group 2 (GII), PRP; group 3 (GIII): λ660 nm; group 4 (GIV), λ830 nm; group 5 (GV), PRP + λ660 nm; and group 6 (GVI), PRP + λ830 nm. The protocol used was power density 0.35 W/cm(2), energy 0.2 J, energy density 7.0 J/cm(2), time 20 s per irradiated point, and number of points 3. Animals in groups GII, GV, and GVI received treatment with PRP, consisting of a single dose of 0.2 mL directly into the surgical site, on top of the tenotomy. Animals were killed on the 13th day post-tenotomy and their tendons were surgically removed for a quantitative analysis using polarization microscopy. The percentages of collagen fibers of types I and III were expressed as mean ± SD. Higher values of collagen fibers type I were obtained for groups GV and GVI when compared with all other groups (p < 0.05), whereas groups GIII and GIV showed no significant difference between them (p > 0.05). For collagen type III, a significant difference was observed between GII and all other groups (p < 0.5), but no significant difference was found between GIII and GIV and between GV and GVI. Results showed that the deposition of collagen type I was higher when treatment with PRP and LLLT was combined, suggesting a faster regeneration of the tendon.
authors: Biomedical Engineering Center, Camilo Castelo Branco University (UNICASTELO), Estrada Dr. Altino Bondesan, 500, Distrito de Eugênio de Melo, 12247-004, São José dos Campos, São Paulo, Brazil, danillo.barbosa@hotmail.com.
authors: Danillo
authors: D
authors: Barbosa
authors: Renato Aparecido
authors: RA
authors: de Souza
authors: Wellington Roberto Gomes
authors: WR
authors: de Carvalho
authors: Murilo
authors: M
authors: Xavier
authors: Paula Kariluce
authors: PK
authors: de Carvalho
authors: Tereza Cristina Rodrigues
authors: TC
authors: Cunha
authors: Emilia Ângela Loschiavo
authors: EÂ
authors: Arisawa
authors: Landulfo
authors: L
authors: Silveira
authors: Antonio Balbin
authors: AB
authors: Villaverde
mesh_terms: D000818:Animals; D002111:Calcaneus; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D003131:Combined Modality Therapy; D028022:Low-Level Light Therapy; D008297:Male; D053657:Platelet-Rich Plasma; D051381:Rats; D017208:Rats, Wistar; D013708:Tendon Injuries / Q000473:pathology / Q000532:radiotherapy* / Q000628:therapy*; D058971:Tenotomy; D014945:Wound Healing / Q000502:physiology / Q000528:radiation effects
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III