Tailoring photobiomodulation to enhance tissue regeneration.

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

Bioactive Zinc(II) complex incorporated PCL/gelatin electrospun nanofiber enhanced bone tissue regeneration.

Bone tissue regeneration is augmented by biocompatible nanofiber scaffolds, that supports reliable and enhanced bone formation. Zinc is an essential mineral that is vital for routine skeletal growth and it emerges to be able to improve bone regeneration. Phytochemicals, particularly flavonoids have achieved prominent interest for their therapeutic ability, they have demonstrated promising effects on bone by encouraging osteoblastogenesis, which finally leads to bone formation. In this study, we have synthesized bioactive zinc(II) quercetin complex material and used for nanofibers scaffold fabrication to enhance bone tissue regeneration property. Two derivatives of zinc(II) quercetin complexes [(Zn(quercetin) (H2O)2) (Zn+Q), and Zn(quercetin)(phenanthroline) (Zn+Q(PHt)) have been synthesized and characterized using UV-Visible spectrophotometer and Fourier Transform-IR spectroscopy. The UV-Visible absorption and IR spectra prove the B-ring chelation of the flavonoid quercetin to zinc(II) rather C-ring chelation. The potential ability of the above synthesized metal complexes on osteogenesis and angiogenesis have been studied. Besides the bioactivity of the metal complexes, the control quercetin has also been examined. The chick embryo chorioallantoic membrane (CAM) assay demonstrated that the angiogenic parameters were increased by the (Zn+Q(PHt)) complex. Amongst, (Zn+Q(PHt)) complex showed significant activity and thereby this complex has been further examined for the bone tissue activity by incorporating the complex into a nanofiber through electrospinning method. At the molecular level, Runx2, mRNA and protein, ALP and type 1 collagen mRNAs, and osteoblast-specific microRNA, pre-mir-15b were examined using real time RT-PCR and Western blot assay. Histology studies showed that the (PCL/gelatin/Zn+Q(PHt)) was biocompatibility in-ovo. Overall, the present study showed that quercetin-zinc complex (Zn+Q(PHt)) incorporated into PCL/gelatin nanofiber can act as a pharmacological agent for treating bone associated defects and promote bone regeneration.

Polymeric Micelle of a Gelatin-Oleylamine Conjugate: A Prominent Drug Delivery Carrier for Treating Triple Negative Breast Cancer Cells.

Protein-based polymeric micelles are proven as effective colloidal drug carriers due to a high drug loading efficiency, sustained release, biocompatibility, and ease of permeation into the cell. Gelatin-based polymeric micelles find applications in treating rare cancerous cells like triple negative breast cancer cells (TNBC), which do not overexpress receptors on its surface. In the present work, we have modified the hydrophilic nature of gelatin into amphiphilic by conjugating with oleylamine using genipin as a cross-linking agent. Owing to amphiphilicity, gelatin-oleylamine conjugate (GOC) self-assembles to form micelles in the aqueous medium. NMR, FTIR, and UV-vis characterizations were used to identify cross-linkage between gelatin and oleylamine, while the results of DLS, confocal, and TEM confirmed aggregation of GOC monomers into micelles. Fluorescence measurement has revealed that the critical micellar concentration of GOC was 0.04 ± 0.01 mg/mL. According to DLS measurements, hydrodynamic size, ζ potential, and polydispersity index of GOC micelles were 230.6 ± 0.4 d. nm, -23.4 ± 0.2 mV, and 0.175 ± 0.008, respectively, proving its colloidal stability in solution at pH 7.4. Catechin was taken as a model antioxidant drug, and drug encapsulation efficiency of GOC micelle was determined to be 62 ± 3%. The cytotoxicity, fluorescent cell imaging, and flow cytometry analyses revealed that TNBC-type cells (MDA-MB-231) internalized drug-bound GOC nanocarriers (CT-GOC) and were involved in cell cycle arrest through G2/M phase-inducing cellular apoptosis. Further, CT-GOC exhibited a higher cellular toxicity to MDA-MB-231 cancerous cells but not in normal cells (NIH-3T3). The overall outcomes of physicochemical and biological measurements suggest that the prepared GOC micelles might be a promising drug carrier for novel anticancer agents in TNBC chemotherapy.