Subfractions of enamel matrix derivative differentially influence cytokine secretion from human oral fibroblasts.

Enamel matrix derivative is used to promote periodontal regeneration during the corrective phase of the treatment of periodontal defects. Our main goal was to analyze the bioactivity of different molecular weight fractions of enamel matrix derivative. Enamel matrix derivative, a complex mixture of proteins, was separated into 13 fractions using size-exclusion chromatography and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and liquid chromatography-electrospray ionization-tandem mass spectrometry. Human periodontal ligament fibroblasts were treated with either enamel matrix derivative or the different fractions. Proliferation and cytokine secretion to the cell culture medium were measured and compared to untreated cells. The liquid chromatography-electrospray ionization-tandem mass spectrometry analyses revealed that the most abundant peptides were amelogenin and leucine-rich amelogenin peptide related. The fractions containing proteins above 20 kDa induced an increase in vascular endothelial growth factor and interleukin-6 secretion, whereas lower molecular weight fractions enhanced proliferation and secretion of interleukin-8 and monocyte chemoattractant protein-1 and reduced interleukin-4 release. The various molecular components in the enamel matrix derivative formulation might contribute to reported effects on tissue regeneration through their influence on vascularization, the immune response, and chemotaxis

In vitro and in vivo performance of nanosized hydroxyapatite particles coated with poly-dl-lactide-co-glycolide as systems for drug delivery of tigecycline

Calcium-phosphate/poly(dl-lactide-co-glycolide) (CP/PLGA) composite biomaterial in granular form showed a high potential in the reconstruction of bone tissue. Compared to pure polymers, the combination of CP with biodegradable polymers used in bone drug delivery systems shows certain advantages. Composite biomaterials in nano particulate (NPs) form may have significant advantages over those in micro- or submicro-particulate form. The purpose of the study presented in this paper has been to examine the possibility of the synthesis of a new nanoparticulate system for controlled and systemic drug delivery with double effect. In the first step, a drug is released from bioresorbable polymer; in the second stage, after resorption of the polymer, non-bioresorbable calcium phosphate remains the chief part of the particle and takes the role of a filler, filling a bone defect. The obtained tigecycline-loaded calcium-phosphate(CP)/poly(dl-lactide-co-glycolide)(PLGA) nano particles contain calcium phosphate coated with bioresorbable polymer and 0.6, 2 and 5wt% tigecycline. The composite was analyzed by FT-IR, XRD, HPLC and AFM methods. The average particle size of the nanocomposite increases with the augmentation of the part of antibiotics, and it ranges from 65 to 95 nm. Release profiles of tigecycline were obtained by UV-VIS spectroscopy in physiological solution at 37oC. Experimental results were analyzed using Peppas and Weibull mathematical models. Based on kinetic parameters, tigecycline release was defined as non-Fickian transport. The in vitro cytotoxicity of the nanocomposite was examined on standard cell lines of MC3T3-E1, in vitro. The obtained low values of LDH activity (under 37%) indicate low cytotoxicity level. Inhibition of bacteria in aerobic and anaerobic conditions in vitro was analyzed after 1, 2 and 3 weeks. The behaviour of the composite under real-life conditions was analyzed through implantation of the nanocomposite into living organisms, in vivo. The system with the lowest tigecycline content proved to be an adequate system for local and controlled release

Advanced hydrogels based on natural macromolecules: chemical routes to achieve mechanical versatility

Advances in synthetic routes to chemically modify natural macromolecules such as polysaccharides and proteins have allowed designing functional hydrogels able to tackle current challenges in the biomedical field. Hydrogels are hydrophilic three-dimensional systems able to absorb or retain a large volume of water, prepared from a low percentage of precursor macromolecules. The typical fragile elastic structure of common hydrogel formulations often limits their usage. Three main fabrication strategies involving several compounds or multimodified materials known as double networks, dual-crosslinked networks, and interpenetrating networks have been explored to impart mechanical strength to hydrogels. Widely investigated for synthetic polymers, these approaches allow obtaining added-value hydrogels with a large spectrum of mechanical properties. Advances in the development of such hydrogels with biomacromolecules as main constituent materials have enabled the fabrication of hydrogels with improved key properties for medical use, including biocompatibility, controlled release of active substances and tailored biodegradability, while exploring sustainable sources. This review describes recent advances in the use of proteins, as well as natural and semi-synthetic polymers for the fabrication of hydrogels for biomedical applications. Structures processed via double network, dual-crosslinked, or interpenetrating network strategies are reviewed, and emphasis is given to the type of chemical modifications and reactions, as well as the covalent and non-covalent interactions/bonds involved in those mechanisms.publishe

Leucine‐Rich Amelogenin Peptide: A Candidate Signaling Molecule During Cementogenesis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141564/1/jper1126.pd

In vitro evaluation of a multifunctional nano drug delivery system based on tigecycline-loaded calcium-phosphate/ poly-DL-lactide-co-glycolide

Most drug delivery systems as treatment modalities for osteomyelitis have not been evaluated for resistant infections. Tigecycline (TG) is an antimicrobial agent that could be used in the treatment of multi-drug-resistant orthopedic infections. The objective of this in vitro study has been to determine what dosage of TG causes changes in the morphology and number of osteoblasts. We have also investigated whether nanoparticulate tigecycline-loaded calcium-phosphate/poly-DL-lactide-co-glycolide is biocompatible and whether it could release bioactive TG in a controlled manner during the observation time. The cytotoxicity was tested by analyzing the release of lactate dehydrogenase from dead osteoblasts to the medium. Staphylococcus aureus was used to verify the antibacterial effect of the multifunctional drug delivery system. At concentrations as achieved by local application, TG caused high toxic effect and impaired the normal osteoblastic morphology. The nanoparticulate multifunctional drug delivery system showed good compatibility and antibacterial effect during the observation time and thus appears to be suitable for the treatment of osteomyelitis caused by multi-drug-resistant microbes.This is accepted peer-reviewed version of the article: Ignjatović, N. L., Ninkov, P., Sabetrasekh, R., Lyngstadaas, S. P., & Uskoković, D. P. (2014). In vitro evaluation of a multifunctional nano drug delivery system based on tigecycline-loaded calcium-phosphate/poly-DL-lactide-co-glycolide. Bio-medical materials and engineering, 24(4), 1647-1658. [https://dx.doi.org/10.3233/BME-140978]Published version: [https://vinar.vin.bg.ac.rs/handle/123456789/7504

In Vitro Osteogenic Properties of Two Dental Implant Surfaces

Current dental implant research aims at understanding the biological basis for successful implant therapy. The aim of the study was to perform a full characterization of the effect of two commercial titanium (Ti) surfaces, OsseoSpeed and TiOblast, on the behaviour of mouse preosteoblast MC3T3-E1 cells. The effect of these Ti surfaces was compared with tissue culture plastic (TCP). In vitro experiments were performed to evaluate cytotoxicity, cell morphology and proliferation, alkaline phosphatase activity, gene expression, and release of a wide array of osteoblast markers. No differences were observed on cell viability and cell proliferation. However, changes were observed in cell shape after 2 days, with a more branched morphology on OsseoSpeed compared to TiOblast. Moreover, OsseoSpeed surface increased BMP-2 secretion after 2 days, and this was followed by increased IGF-I, BSP, and osterix gene expression and mineralization compared to TiOblast after 14 days. As compared to the gold standard TCP, both Ti surfaces induced higher osteocalcin and OPG release than TCP and differential temporal gene expression of osteogenic markers. The results demonstrate that the gain of using OsseoSpeed surface is an improved osteoblast differentiation and mineralization, without additional effects on cell viability or proliferation

Co-operative mineralization and protein self-assembly in amelogenesis: silica mineralization and assembly of recombinant amelogenins in vitro

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73342/1/j.1600-0722.2006.00288.x.pd