Three-dimensional bioglass-collagen-phosphatidylserine scaffolds designed with functionally graded structure and mechanical features

Polymeric and Composite Carriers of Protein and Non-Protein Biomolecules for Application in Bone Tissue Engineering

Conventional intake of drugs and active substances is most often based on oral intake of an appropriate dose to achieve the desired effect in the affected area or source of pain. In this case, controlling their distribution in the body is difficult, as the substance also reaches other tissues. This phenomenon results in the occurrence of side effects and the need to increase the concentration of the therapeutic substance to ensure it has the desired effect. The scientific field of tissue engineering proposes a solution to this problem, which creates the possibility of designing intelligent systems for delivering active substances precisely to the site of disease conversion. The following review discusses significant current research strategies as well as examples of polymeric and composite carriers for protein and non-protein biomolecules designed for bone tissue regeneration.

The Local Release of Teriparatide Incorporated in 45S5 Bioglass Promotes a Beneficial Effect on Osteogenic Cells and Bone Repair in Calvarial Defects in Ovariectomized Rats

With the increase in the population's life expectancy, there has also been an increase in the rate of osteoporosis, which has expanded the search for strategies to regenerate bone tissue. The ultrasonic sonochemical technique was chosen for the functionalization of the 45S5 bioglass. The samples after the sonochemical process were divided into (a) functionalized bioglass (BG) and (b) functionalized bioglass with 10% teriparatide (BGT). Isolated mesenchymal cells (hMSC) from femurs of ovariectomized rats were differentiated into osteoblasts and submitted to in vitro tests. Bilateral ovariectomy (OVX) and sham ovariectomy (Sham) surgeries were performed in fifty-five female Wistar rats. After a period of 60 days, critical bone defects of 5.0 mm were created in the calvaria of these animals. For biomechanical evaluation, critical bone defects of 3.0 mm were performed in the tibias of some of these rats. The groups were divided into the clot (control) group, the BG group, and the BGT group. After the sonochemical process, the samples showed modified chemical topographic and morphological characteristics, indicating that the surface was chemically altered by the functionalization of the particles. The cell environment was conducive to cell adhesion and differentiation, and the BG and BGT groups did not show cytotoxicity. In addition, the experimental groups exhibited characteristics of new bone formation with the presence of bone tissue in both periods, with the BGT group and the OVX group statistically differing from the other groups (p < 0.05) in both periods. Local treatment with the drug teriparatide in ovariectomized animals promoted positive effects on bone tissue, and longitudinal studies should be carried out to provide additional information on the biological performance of the mutual action between the bioglass and the release of the drug teriparatide.

Review of the Applications of Biomedical Compositions Containing Hydroxyapatite and Collagen Modified by Bioactive Components

Regenerative medicine is becoming a rapidly evolving technique in today's biomedical progress scenario. Scientists around the world suggest the use of naturally synthesized biomaterials to repair and heal damaged cells. Hydroxyapatite (HAp) has the potential to replace drugs in biomedical engineering and regenerative drugs. HAp is easily biodegradable, biocompatible, and correlated with macromolecules, which facilitates their incorporation into inorganic materials. This review article provides extensive knowledge on HAp and collagen-containing compositions modified with drugs, bioactive components, metals, and selected nanoparticles. Such compositions consisting of HAp and collagen modified with various additives are used in a variety of biomedical applications such as bone tissue engineering, vascular transplantation, cartilage, and other implantable biomedical devices.

Developing a novel resorptive hydroxyapatite-based bone substitute for over-critical size defect reconstruction: physicochemical and biological characterization and proof of concept in segmental rabbit's ulna reconstruction

The aim of this study was to develop novel hydroxyapatite (HAP)-based bioactive bone replacement materials for segmental osteotomy reconstruction. Customized three-dimensional (3D) bone construct was manufactured from nanohydroxyapatite (nHAP) with poly(lactide-co-glycolide) (PLGA) coating using 3D models derived from the computed tomography (CT) scanning of the rabbit's ulna and gradient 3D printing of the bone substitute mimicking the anatomical shape of the natural bone defect. Engineered construct revealed adequate micro-architectural design for successful bone regeneration having a total porosity of 64% and an average pore size of 256 μm. Radiography and micro-CT analysis depicted new bone apposition through the whole length of the reconstructed ulna with a small area of non-resorbed construct in the central area of defect. Histological analysis revealed new bone formation with both endochondral and endesmal type of ossification. Immunohistochemistry analysis depicted the presence of bone formation indicators - bone morphogenetic protein (BMP), osteocalcin (OCN) and osteopontin (OPN) within newly formed bone. Manufactured personalized construct acts as a "smart" responsive biomaterial capable of modulating the functionality and potential for the personalized bone reconstruction on a clinically relevant length scale.