Mineralization regulation and biological influence of bioactive glass-collagen-phosphatidylserine composite scaffolds

Biomechanical Characteristics and Analysis Approaches of Bone and Bone Substitute Materials

Bone has a special structure that is both stiff and elastic, and the composition of bone confers it with an exceptional mechanical property. However, bone substitute materials that are made of the same hydroxyapatite (HA) and collagen do not offer the same mechanical properties. It is important for bionic bone preparation to understand the structure of bone and the mineralization process and factors. In this paper, the research on the mineralization of collagen is reviewed in terms of the mechanical properties in recent years. Firstly, the structure and mechanical properties of bone are analyzed, and the differences of bone in different parts are described. Then, different scaffolds for bone repair are suggested considering bone repair sites. Mineralized collagen seems to be a better option for new composite scaffolds. Last, the paper introduces the most common method to prepare mineralized collagen and summarizes the factors influencing collagen mineralization and methods to analyze its mechanical properties. In conclusion, mineralized collagen is thought to be an ideal bone substitute material because it promotes faster development. Among the factors that promote collagen mineralization, more attention should be given to the mechanical loading factors of bone.

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.

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.

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

The development of scaffolds featuring spatiotemporal controlled release of drugs is highly desirable. The goal of this study is to construct an inhomogeneous scaffold with gradient pore structure from top layer to bottom layer. The scaffolds were prepared using bioglass (BG), phosphatidylserine (PS) and steroidal saponins (SS) loaded collagen (COL) microparticles as the main components. The resulting scaffold constructs were characterized in terms of their morphology, drug release kinetics and mechanisms, as well as macroscopic form stability and mechanical properties. Pore interconnectivity and graded distribution were demonstrated using scanning electron microscopy (SEM). Such constructs have been further shown to be advantageous for temporal and spatial control of drug release and deposition in the scaffolds, with a potential to repair bone defect more precisely and effectively. Changes in the BG content resulted in distinct macroscopic form stability and mechanical properties to scaffolds. An increase in the BG content in scaffolds led to less volume swell as well as higher ultimate strength and compressive modulus, which makes the scaffolds mechanically adjustable according to certain structures and properties of different bone defect sites. The developed scaffolds may show promise for promoting bone tissue regeneration.

Effect of steroidal saponins-loaded nano-bioglass/phosphatidylserine/collagen bone substitute on bone healing

The objective of this study was to investigate the therapeutic potential of nano-bioglass/phosphatidylserine/collagen (nBG/PS/COL) scaffolds loaded with steroidal saponins as an inducer factor for skeletal defects. The drugs-encapsulated bone substitute was prepared by loading steroidal saponins-collagen microsphere suspension in nano-bioglass and phosphatidylserine (PS) composite. The scaffolds possess an interconnected porous structure with a porosity of about 82.3%. The pore size ranges from several micrometers up to about 400 μm. The drug release assays showed the long-term sustained release of steroidal saponins from the scaffolds with effective and safe bioactivity. Moreover,

On the Collagen Mineralization. A Review

Collagen mineralization (CM) is a challenging process that has received a lot of attention in the past years. Among the reasons for this interest, the key role is the importance of collagen and hydroxyapatite in natural bone, as major constituents. Different protocols of mineralization have been developed, specially using simulated body fluid (SBF) and many methods have been used to characterize the systems obtained, starting with methods of determining the mineral content (XRD, FTIR, Raman, High-Resolution Spectral Ultrasound Imaging), continuing with imaging methods (AFM, TEM, SEM, Fluorescence Microscopy), thermal analysis (DSC and TGA), evaluation of the mechanical and biological properties, including statistical methods and molecular modeling. In spite of the great number of studies regarding collagen mineralization, its mechanism, both in vivo and in vitro, is not completely understood. Some of the methods used in vitro and investigation methods are reviewed here.

Combining collagen and bioactive glasses for bone tissue engineering: a review

Collagen (COL), the most abundant protein in mammals, offers a wide range of attractive properties for biomedical applications which are the result of its biocompatibility and high affinity to water. However, due to the relative low mechanical properties of COL its applications are still limited. To tackle this disadvantage of COL, especially in the field of bone tissue engineering, COL can be combined with bioactive inorganic materials in a variety of composite systems. One of such systems is the collagen-bioactive glass (COL-BG) composite family, which is the theme of this Review. BG fillers can increase compressive strength and stiffness of COL-based structures. This article reviews the relevant literature published in the last 15 years discussing the fabrication of a variety of COL-BG composites. In vitro cell studies have demonstrated the osteogenic, odontogenic, and angiogenic potential of these composite systems, which has been confirmed by stimulating specific biochemical indicators of relevant cells. Bony integration and connective tissue vessel formation have also been studied by implantation of the composites in vivo. Areas of future research in the field of COL-BG systems, based on current challenges, and gaps in knowledge are highlighted.