A biocomplex to repair experimental critical size defects associated with photobiomodulation therapy

Abstract

Background: The association of scaffolds to repair extensive bone defects can contribute to their evolution and morphophysiological recomposition. The incorporation of particulate biomaterials into three-dimensional fibrin bioproducts together with photobiomodulation therapy (PBM) has potential and can improve regenerative medicine procedures. The objective of this experiment was to evaluate the effects of PBM therapy on critical size defects filled with xenogenic bone substitute associated with fibrin biopolymer. Methods: A critical defect of 8 mm was performed in 36 Wistar male adult rats that were divided into four groups. Groups BC and BC-PBM were defined as controls with defects filled by a clot (without or with PBM, respectively) and groups XS and XS-PBM that comprised those filled with biocomplex Bio-Oss TM in association with fibrin biopolymer. PBM was applied immediately after the surgery and three times a week every other day, with the parameters: wavelength of 830 nm, energy density 6.2 J/cm 2 , output power 30 mW, beam area of 0.116 cm 2 , irradiance 0.258,62 W/cm 2 , energy/point 0.72 J, total energy 2.88 J. Fourteen and 42 days after the surgery, animals were euthanatized and subjected to microtomography, qualitative and quantitative histological analysis.

Effects of a Biocomplex Formed by Two Scaffold Biomaterials, Hydroxyapatite/Tricalcium Phosphate Ceramic and Fibrin Biopolymer, with Photobiomodulation, on Bone Repair

“…The increasing bone formation observed over time in this research was also reported in studies that used similar methodologies [ 20 , 44 ]. These data demonstrate that PBM may have positive effects on bone tissue, improving the quality and density of newly formed bone [ 44 , 46 , 47 ].…”

“…In this period of analysis, it is possible to observe the presence of vascular sprouts in the G4/BFB + PBM group, which may be due to the effects of PBM therapy on the local microcirculation [ 46 ]. In addition to PBM, the fibrin biopolymer also contributed to stimulate angiogenic factors and neovascularization, as observed in previous studies [ 20 , 44 ]. The analyses performed at 42 postoperative days shows that there was an advance in bone formation in all experimental groups, but without the complete closure of the defects.…”

“…The process of new bone formation that occurred over the 42 days was also favored by the combination of the biomaterial with the fibrin polymer. This association of biopolymers constitutes a promising strategy to regenerate bone defects since the fibrin favors the incorporation of the biomaterial at the lesion site [ 44 ].…”

“…Tissue regeneration was also improved by PBM therapy, which stimulates bone formation and favors the integration process of the biomaterial stabilized with fibrin [ 44 , 45 ]. The increasing bone formation observed over time in this research was also reported in studies that used similar methodologies [ 20 , 44 ]. These data demonstrate that PBM may have positive effects on bone tissue, improving the quality and density of newly formed bone [ 44 , 46 , 47 ].…”

“…A study carried out with a similar biocomplex, except that the biomaterial was a bone substitute established in preclinical and clinical studies (Bio-Oss ® bone substitute, Geistlich Pharma AG, Wolhusen, Switzerland), with the same laser therapy protocol, showed similar results in bone neoformation increased by PBM in which the biocomplex created a favorable microenvironment for an adequate repair process as an innovative drug delivery system [ 44 ]. The phase I/II clinical trial involving the treatment of chronic venous ulcers with FB has been completed and its results were recently published [ 17 ].…”