Fabrication of anodic and atomic layer deposition-alumina coated titanium implants for effective osteointegration applications.

Biomimicking the chemical, mechanical, and topographical properties of bone on an implant model is crucial to obtain rapid and effective osteointegration, especially for the large-area fractures of the skeletal system. Titanium-based biomaterials are more frequently preferred in clinical use in such cases and coating these materials with oxide layers having chemical/nanotopographic properties to enhance osteointegration and implantation success rates has been studied for a long time. The objective of this study is to examine the high and rapid mineralization potential of anodized aluminum oxide (AAO) coated and atomic layer deposition (ALD)-alumina coated titanium substrates on large deformation areas with difficult spontaneous healing.

Bioinspired Collagen/Gelatin Nanopillared Films as a Potential Implant Coating Material.

Collagen-based Sharpey's fibers are naturally located between alveolar bone and tooth, and they have critical roles in a well-functioning tooth such as mechanical stability, facile differentiation, and disease protection. The success of Sharpey's fibers in these important roles is due to their unique location, vertical alignment with respect to tooth surface, as well as their micronanofiber architecture. Inspired by these structures, herein, we introduce the use of nanoporous anodic aluminum oxide molds in a drop-casting setup to fabricate biopolymeric films possessing arrays of uniform Collagen:Gelatin (Col:Gel) nanopillars.

Patients- and tissue-specific bio-inks with photoactivated PRP and methacrylated gelatin for the fabrication of osteochondral constructs.

In osteochondral tissue engineering, while the biochemical and mechanical properties of hydrogels guide stem cell proliferation and differentiation, physical and chemical stimulators also affect the differentiation of stem cells. Herein, we presented a patient and tissue-specific strategy for the development of biomimetic osteochondral constructs with gradient compositions. Osteochondral constructs were fabricated by gradually printing of bio-inks consisting of therapeutic platelet-rich plasma (PRP), adipose tissue-derived mesenchymal stem cells (AdMSCs), and extracellular matrix (ECM) mimetic hydrogel, microwave-assisted methacrylated gelatin (Gel-MA).

Photobiomodulation combined with adipose-derived stem cells encapsulated in methacrylated gelatin hydrogels enhances in vivo bone regeneration.

Reconstruction of bone defects is still a significant challenge. The aim of this study was to evaluate the effect of application of photobiomodulation (PBM) to enhance in vivo bone regeneration and osteogenic differentiation potential of adipose-derived stem cells (ADSCs) encapsulated in methacrylated gelatin (GEL-MA) hydrogels. Thirty-six Sprague-Dawley rats were randomly separated into 3 experimental groups (n = 12 each).

Photo-activated platelet-rich plasma (PRP)-based patient-specific bio-ink for cartilage tissue engineering.

Nowadays, scientists focus on the development of tissue-specific and personalized bio-ink that can be used in 3D bioprinting technologies. Platelet-rich plasma (PRP) is a person-specific source that is used as a therapeutic adjunct for the treatment of cartilage damage because it offers a cocktail of growth factors that are necessary for wound healing and tissue regeneration. However, PRP treatments in the clinic are not satisfactory and require upgrading, especially the point of maintaining bioactivity.

Microwave assisted methacrylation of Kappa carrageenan: A bioink for cartilage tissue engineering.

In this study, we aimed to obtain stable Kappa carrageenan (κCar) hydrogel that could be used as a bioink for cartilage regeneration. For this purpose, we described an effective and considerably faster methacrylation process by using microwave energy. Thus, microwave-methacrylated κCar (Mw-κCar-MA) with ≥85% degree of methacrylation (DM) was synthesized despite the use of a low concentration of methacrylic anhydride (MA) at 1000 W in 5 min.

Sustained release of growth factors from photoactivated platelet rich plasma (PRP).

The goal of this study is to specify the ability of polychromatic light source (PAC), providing effective wavelengths in the range of 600-1200 nm (near-infrared region, NIR), to activate human platelets in platelet-rich plasma (PRP) and to achieve sustained and controlled release of growth factors from photoactivated platelets. PRP was isolated from human blood and treated with PAC in different time intervals during 1, 5 and 10 min from 10 cm distance to the platelets. ATP secretion and then, calcium release from platelets significantly increased after light application.

Highly Methacrylated Gelatin Bioink for Bone Tissue Engineering.

Methacrylated gelatin (Gel-MA) is a commonly used biomaterial in bioprinting applications. The Gel-MA synthesis procedure is inadequate and needs to be improved, particularly from the point of optimization and efficacy. We report a significantly faster (by 5 min) and effective method to controllably synthesize Gel-MA using microwave energy (Mw at 1000 W power) with ≥90% degree of methacrylation (DM) even with the use of a very low concentration of methacrylic anhydride (MA).

Photobiomodulation with polychromatic light increases zone 4 survival of transverse rectus abdominis musculocutaneous flap.

Objective: The aim of this study was to evaluate the effect of relatively novel approach of application of polychromatic light waves on flap survival of experimental musculocutaneous flap model and to investigate efficacy of this modality as a delay procedure to increase vascularization of zone 4 of transverse rectus abdominis musculocutaneous (TRAM) flap.

Methods: Twenty-one Wistar rats were randomized and divided into 3 experimental groups (n = 7 each). In group 1 (control group), after being raised, the TRAM flap was sutured back to its bed without any further intervention.

A bioprintable form of chitosan hydrogel for bone tissue engineering.

Bioprinting can be defined as 3D patterning of living cells and other biologics by filling and assembling them using a computer-aided layer-by-layer deposition approach to fabricate living tissue and organ analogs for tissue engineering. The presence of cells within the ink to use a 'bio-ink' presents the potential to print 3D structures that can be implanted or printed into damaged/diseased bone tissue to promote highly controlled cell-based regeneration and remineralization of bone. In this study, it was shown for the first time that chitosan solution and its composite with nanostructured bone-like hydroxyapatite (HA) can be mixed with cells and printed successfully.

A Biomimetic Alternative to Synthetic Hydroxyapatite: "Boron-Containing Bone-Like Hydroxyapatite" Precipitated From Simulated Body Fluid.

Background: Biological hydroxyapatite (HA), has several mechanical and physical advantages over the commercially available synthetic apatite (CAP-HA). The aim of this in vivo study was to investigate the effect of osteoinductive "bone-like hydroxyapatite" obtained from simulated body fluid (SBF) combined with osteoinductive "boron" (B) on bone healing.

Materials: Bone like nanohydroxyapatite (SBF-HA) was precipitated from 10× simulated body fluid (10×SBF).

Sustained release of 17β-estradiol stimulates osteogenic differentiation of adipose tissue-derived mesenchymal stem cells on chitosan-hydroxyapatite scaffolds.

The aim of this study was to develop a 17β-estradiol (E2)-releasing scaffold-nanoparticle system in order to promote osteogenic differentiation of rat adipose tissue-derived mesenchymal stem cells (AdMSCs) for bone tissue regeneration. E2-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles with a diameter of ∼240 nm were produced via an emulsion-diffusion-evaporation method. Because of its higher encapsulation efficiency (54%), PLGA, which has a 65:35 composition, was chosen for the preparation of nanoparticles.

Estrogen as a novel agent for induction of adipose-derived mesenchymal stem cells for osteogenic differentiation: in vivo bone tissue-engineering study.

Background: This study investigated whether the in vivo osteogenic differentiation potential of adipose-derived mesenchymal stem cells is enhanced by 17β-estradiol.

Methods: Thirty Sprague-Dawley rats were randomized and divided into five experimental groups. For the surgical procedure, biparietal full-thickness bone defects (7 mm in diameter) were created.