The Effects of 5% 5-Aminolevulinic Acid Gel and Red Light (ALAD-PDT) on Human Fibroblasts and Osteoblasts

Abstract

This study aimed to evaluate the effects of a new photodynamic protocol (ALAD-PDT), consisting of 5% 5-aminolevulinic acid-gel and 630 nm-LED, already used for antibacterial effects in the treatment of periodontitis, on human gingival fibroblasts (HGF) and primary human osteoblasts (HOB). HGF and HOB were incubated with different ALAD concentrations for 45 min, and subsequently irradiated with 630 nm-LED for 7 min. Firstly, the cytotoxicity at 24 h and proliferation at 48 and 72 h were assessed. Then the intracellular content of the protoporphyrin IX (PpIX) of the ROS and the superoxide dismutase (SOD) activity were investigated at different times. Each result was compared with untreated and unirradiated cells as the control. Viable and metabolic active cells were revealed at any concentrations of ALAD-PDT, but only 100-ALAD-PDT significantly enhanced the proliferation rate. The PpIX fluorescence significantly increased after the addition of 100-ALAD, and decreased after the irradiation. Higher ROS generation was detected at 10 min in HGF, and at 30 min in HOB. The activity of the SOD enzyme augmented at 30 min in both cell types. In conclusion, ALAD-PDT not only showed no cytotoxic effects, but had pro-proliferative effects on HGF and HOB, probably via ROS generation.

Functionalization of a Cortical Membrane with a Photodynamic Protocol

“…In a recent study, cortical lamina has been functionalized with graphene oxide to improve the biological properties of the membrane [ 28 ]. Considering that an antibacterial photodynamic protocol (ALAD-PDT), in vitro also demonstrated a pro-proliferative effect on fibroblasts and osteoblasts [ 11 , 12 , 13 , 33 ], the biological activities of the lamina were also investigated after the application of ALAD-PDT protocol, in TEST 2 [ 17 , 18 ]. The cultured Lamina membranes with HOBs were subjected to the application of ALAD-PDT consisting of incubation for 45 min with a gel containing 5% of 5-aminolevulinic acid and irradiation for 7 min with a red light at 630 nm, to check, whether this photodynamic protocol could improve the early adhesion and proliferation of cells.…”

“…Some authors have hypothesized that the antifungal activity of the ALAD-PDT protocol shown against Candida albicans could be not only the result of ROS production but also the consequence of other properties intrinsic to the ALAD gel formulation, such as the low pH. With respect to other photodynamic therapy, the novelty of ALAD-PDT is that it was also able to promote fibroblasts and osteoblasts proliferation and osteogenic bone marker increments [ 17 , 18 ]. This effect opens up a possible clinical use of the ALAD-PDT protocol during guided bone regeneration (GBR) as an adjunctive aid for both antibacterial activity and accelerated healing.…”

“…In those studies, all photodynamic protocols were applied as antimicrobial treatments and occurred previously to guide bone regeneration, which was carried out using xenogenic bone and resorbable collagen membranes. In view of our recent in vitro studies concerning the pro-proliferative effects of ALAD-PDT protocol on fibroblasts and osteoblasts [ 17 , 18 ], the present study proposed innovative employment of the photodynamic treatment by hypothesizing that the application of ALAD-PDT on curved lamina could promote its osteoconductive properties to achieve bone gain during GBR. Thus, the second objective was to functionalize the curved lamina with the application of the ALAD-PDT protocol in order to investigate the effects of ALAD-PDT on the adhesion, the growth, and the mineralization activity of HOBs seeded on the lamina.…”

Photodynamic therapy in periodontitis: A narrative review

“…54 PDT also supports HGF activities like proliferation, migration, and gene expression related to wound healing, [47][48][49]52,53 and promotes HOB proliferation and differentiation with altered OPG and RANKL expression. 29,47,48,[64][65][66][67] Guangzhou…”

“…And ALA-PDT even promotes HGFs proliferation and adhesion in vitro. 48,49 Astuti et al 32 showed that the doxycyclineinduced PDT increased the presence of fibroblasts within the periodontal tissue of Wistar rats exhibiting periodontitis. However, some findings indicate that indocyanine green (ICG)-mediated PDT induces apoptosis in HGFs at the transcriptome level.…”