biomimetic Hydrogel/apatite Nanocomposite Scaffolds for Bone Regeneration

2005 ◽  
Vol 897 ◽  
Author(s):  
Esmaiel Jabbari
Keyword(s):  
Ethylene Oxide ◽  
Bone Regeneration ◽  
Cell Attachment ◽  
Degradation Kinetics ◽  
Bone Matrix ◽  
Biologically Active ◽  
Structural Support ◽  
Cellular Environment ◽  
Gel Phase ◽  
And Migration

AbstractBone is a composite material consisting of aqueous gel and mineral phases. The aqueous gel phase gives bone its form and contributes to its ability to resist tension, while the mineral component resists compression. The combination of a hard inorganic phase and an elastic gel network provides bone with unique mechanical properties as well as a medium for diffusion and release of biologically active agents and it also facilitates communication with the cellular environment. A tissue engineered synthetic biomaterial as a scaffold for bone regeneration should provide temporary structural support to the reconstructed region and a medium for solubilization, diffusion, release of nutrients and growth factors, and their interactions with cells. In this work, the material and biologic properties of a novel synthetic matrix metalloproteinase (MMP) degradable hydrogel/apatite nanocomposite is investigated for its usefulness as a model matrix to mimic the gel and mineral components of the bone matrix and to fabricate aqueous-based scaffolds for bone regeneration. The gel phase is made from poly(lactide-ethylene oxide-fumarate), hereafter designated as PLEOF, terpolymer in which the water content can be adjusted by changing the ratio of the hydrophobic (lactide) to hydrophilic (ethylene oxide) oligomers. The hydrogel and apatite phases are crosslinked using an MMP degradable peptide crosslinker to modulate the matrix degradation kinetics with the migration of bone marrow stromal (BMS) cells. The results demonstrate that MMP degradable scaffolds fabricated from the PLEOF hydrogel and apatite nanoparticles are biocompatible and support cell attachment and migration.

Engineered Bone from Polyglycolic Acid Polymer Scaffold and Periosteum

1995 ◽  
Vol 394 ◽  
Author(s):  
Tae Ho Kim ◽  
Carol Jannetta ◽  
Joseph P. Vacanti ◽  
Joseph Upton ◽  
Charles A. Vacanti
Keyword(s):  
Bone Tissue ◽  
Cell Attachment ◽  
Bone Matrix ◽  
Polyglycolic Acid ◽  
Polymer Scaffold ◽  
Periosteal Cell ◽  
Subcutaneous Space ◽  
Periosteal Cells ◽  
And Migration ◽  
And Cartilage

AbstractThe ability to create bone from periosteum and biodegradable polymer may have significant utility in reconstructive orthopedic and plastic surgery. Polyglycolic acid (PGA) serves as a biodegradable matrix which can be configured to a desirable shape and structure. This study was conducted to generate new bone tissue from periosteum and PGA polymer and to compare the tissue to the bone tissue generated from periosteal cells seeded onto PGA polymer. Bovine periosteum, harvested from fresh calf limbs, was placed either directly onto PGA polymer (1 cm2) or onto tissue culture dishes for periosteal cell isolation. In Medium 199 media with antibiotics and ascorbic acid, the periosteum/PGA construct was cultured for one week, then implanted into the dorsal subcutaneous space of nude mice. Periosteal cells, cultured from pieces of periosteum for two weeks, were isolated into cell suspension and seeded (˜l-3× 107 cells) onto PGA polymer (1 cm2); after one week in culture, the periosteal cell-seeded polymer was implanted into the subcutaneous space of athymic mice. Specimens, harvested at 4, 8, and 14 week intervals, were evaluated grossly and histologically. The periosteum/PGA constructs showed an organized cartilage matrix with early evidence of bone formation at 4 weeks, a mixture of bone and cartilage at 8 weeks, and a complete bone matrix at 14 weeks. Constructs created from periosteal cells seeded onto polymer showed presence of disorganized cartilage at 4 and 8 weeks, and a mixture of bone and cartilage at 14 weeks. Periosteum placed directly onto polymer will form an organized cartilage and bone matrix earlier than constructs formed from periosteal cell-seeded polymer. This data suggests that PGA is an effective scaffold for periosteal cell attachment and migration to produce bone which may offer new approaches to reconstructive surgery.

scholarly journals Perivascular adipose tissue: more than just structural support

2011 ◽  
Vol 122 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Theodora Szasz ◽  
R. Clinton Webb
Keyword(s):  
Adipose Tissue ◽  
Current Knowledge ◽  
Vascular Biology ◽  
Biologically Active ◽  
Perivascular Adipose Tissue ◽  
Structural Support ◽  
Wide Range ◽  
And Migration ◽  
Obesity Hypertension ◽  
And Function

PVAT (perivascular adipose tissue) has recently been recognized as a novel factor in vascular biology, with implications in the pathophysiology of cardiovascular disease. Composed mainly of adipocytes, PVAT releases a wide range of biologically active molecules that modulate vascular smooth muscle cell contraction, proliferation and migration. PVAT exerts an anti-contractile effect in various vascular beds which seems to be mediated by an as yet elusive PVRF [PVAT-derived relaxing factor(s)]. Considerable progress has been made on deciphering the nature and mechanisms of action of PVRF, and the PVRFs proposed until now are reviewed here. However, complex pathways seem to regulate PVAT function and more than one mechanism is probably responsible for PVAT actions in vascular biology. The present review describes our current knowledge on the structure and function of PVAT, with a focus on its role in modulating vascular tone. Potential involvements of PVAT dysfunction in obesity, hypertension and atherosclerosis will be highlighted.

scholarly journals The Short Arm of the Laminin γ2 Chain Plays a Pivotal Role in the Incorporation of Laminin 5 into the Extracellular Matrix and in Cell Adhesion

2001 ◽  
Vol 153 (4) ◽  
pp. 835-850 ◽  
Author(s):  
Laurent Gagnoux-Palacios ◽  
Maryline Allegra ◽  
Flavia Spirito ◽  
Olivier Pommeret ◽  
Christine Romero ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Adhesion ◽  
Cell Attachment ◽  
Biologically Active ◽  
Globular Domain ◽  
Stimulated Scattering ◽  
Laminin 5 ◽  
And Migration ◽  
Immunohistochemical Studies ◽  
Adhesion Ligand

Laminin 5 is a basement membrane component that actively promotes adhesion and migration of epithelial cells. Laminin 5 undergoes extracellular proteolysis of the γ2 chain that removes the NH2-terminal short arm of the polypeptide and reduces the size of laminin 5 from 440 to 400 kD. The functional consequence of this event remains obscure, although lines of evidence indicate that cleavage of the γ2 chain potently stimulated scattering and migration of keratinocytes and cancer cells. To define the biological role of the γ2 chain short arm, we expressed mutated γ2 cDNAs into immortalized γ2-null keratinocytes. By immunofluorescence and immunohistochemical studies, cell detachment, and adhesion assays, we found that the γ2 short arm drives deposition of laminin 5 into the extracellular matrix (ECM) and sustains cell adhesion. Our results demonstrate that the unprocessed 440-kD form of laminin 5 is a biologically active adhesion ligand, and that the γ2 globular domain IV is involved in intermolecular interactions that mediate integration of laminin 5 in the ECM and cell attachment.

A cancellous bone matrix system with specific mineralisation degrees for mesenchymal stem cell differentiation and bone regeneration

2019 ◽  
Vol 7 (6) ◽  
pp. 2452-2467 ◽  
Author(s):  
Shijie Liu ◽  
Yiyun Wang ◽  
Jian Wang ◽  
Pengcheng Qiu ◽  
Shengyu Wang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Differentiation ◽  
Mesenchymal Stem Cell ◽  
Bone Regeneration ◽  
Cancellous Bone ◽  
Bone Matrix ◽  
Stem Cell Differentiation ◽  
Matrix System ◽  
Mesenchymal Stem Cell Differentiation ◽  
Regenerative Therapies

Bone regenerative therapies have been explored using various biomaterial systems.

The Poor Osteoinductive Capability of Human Acellular Bone Matrix

2012 ◽  
Vol 35 (12) ◽  
pp. 1061-1069 ◽  
Author(s):  
Yi-Zhou Huang ◽  
Jia-Qin Cai ◽  
Jing Xue ◽  
Xiao-He Chen ◽  
Chao-Liang Zhang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Structural Features ◽  
Nodule Formation ◽  
Porous Network ◽  
Native Bone ◽  
Genes Encoding ◽  
Osteoid Formation ◽  
Stem Cell Niches

Demineralized bone matrix (DBM) has extensive clinical use for bone regeneration because of its osteoinductive and osteoconductive aptitude. It is suggested that the demineralization process in bone matrix preparation is influential in maintaining osteoinductivity; however, relevant investigations, especially into the osteoinductivity of acellular bone matrix, are not often performed. This study addressed the osteoinductive capability of human acellular cancellous bone matrix (ACBM) after subcutaneous implantation in a rat model. The growth and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) seeded in this material were also studied. Without the demineralization process, the ACBM we obtained had an interconnected porous network and the micropores in the surface were clearly exposed. After the ACBM was subcutaneously implanted for 4 months, new osteoid formation was noted but not typical mature bone formation. rBM-MSCs grew well in the ACBM and kept a steady morphology after continuous culture for 28 days. However, no mineralized nodule formation was detected and the expression levels of genes encoding osteogenic markers were significantly decreased. These results demonstrated that human ACBM possess the structural features of native bone and poor osteoinductivity; nonetheless this material helped to preserve the undifferentiated phenotype of rBM-MSCs. Such insights may further broaden our understanding of the application of ACBM for bone regeneration and the creation of stem cell niches.

Surface Immobilization of Synthetic Proteins Via Plasma Polymer Interlayers

1998 ◽  
Vol 544 ◽  
Author(s):  
Hans J Griesser ◽  
Keith M McLean ◽  
Gerrit J Beumer ◽  
Xiaoyi Gong ◽  
Peter Kingshot ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Cell Attachment ◽  
Plasma Layer ◽  
Polymeric Materials ◽  
Covalent Immobilization ◽  
Biologically Active ◽  
Plasma Polymer ◽  
Rf Plasma ◽  
Bulk Materials ◽  
Synthetic Proteins

AbstractCoatings of biologically active molecules on synthetic ”bulk“materials are of much interest for biomedical applications since they can in principle elicit specific, predictable. controlled responses of the host environment to an implanted device. However, issues such as shelf life. storage conditions, biological safety, and enzymatic attack in the biological environment must be considered; synthetic proteins may offer advantages. In this study we investigated the covalent immobilization onto polymeric materials of synthetic proteins which possess some properties that mimic those of the natural protein collagen, particularly the ability to form triple helical structures, and thus may provide similar bio-responses while avoiding enzymatic degradation. In order to perform immobilization of these collagen-like molecules (CLMs) under mild reaction conditions, the bulk materials are first equipped with suitable surface groups using rf plasma methods. Plasma polymer interlayers offer advantages as versatile reactive platforms for the immobilization of proteins and other biologically active molecules. Application of a thin plasma polymer coating from an aldehyde monomer is particularly suitable as it enables direct immobilization of CLMs by reaction with their terminal amine groups, using reductive amination chemistry. An alternative route is via plasma polymer layers that contain carboxylic acid groups and using carbodiimnide chemistry. A third route makes use of alkylamme plasma polymer interlayers, which are less process sensitive than aldehyde and acid plasma coatings. A layer of poly-carboxylic acid compounds such as carboxylic acid terminated PAMAM-starburst dendrimers or carboxymethylated dextran is then attached by carbodiimide chemistry onto the amine plasma layer. Amine-terminated CLMs can then be immobilized onto the poly-carboxylic acid layer. Surface analytical methods have been used to characterize the immobilization steps and to assess the surface coverage. Initial cell attachment and growth assays indicate that the biological performance of the CLMs depends on their amino acid sequence.

scholarly journals STATISTICAL OPTIMIZATION OF GELATIN IMMOBILISATION ON MODIFIED SURFACE PCL MICROCARRIER TO IMPROVE PCL MICROCARRIER COMPATIBILITY

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Nurhusna Samsudin ◽  
Yumi Zuhanis Has-Yun Hashim ◽  
Mohd Azmir Arifin ◽  
Maizirwan Mel ◽  
Hamzah Mohd. Salleh ◽  
...  
Keyword(s):  
Statistical Approach ◽  
Functional Group ◽  
Cell Attachment ◽  
Degradation Kinetics ◽  
Covalent Immobilization ◽  
Optimum Conditions ◽  
Oxygen Functional Group ◽  
Main Challenge ◽  
Modified Surface ◽  
Conventional Cell

Growing cells on microcarriers may have overcome the limitation of conventional cell culture system. However, the main challenge remains at ensuring the surface biocompatibility with cells. Polycaprolactone (PCL), a biodegradable polymer, has received considerable attention because of its excellent mechanical properties and degradation kinetics that suit various applications, but its non-polar hydrocarbon moiety renders it sub-optimal for cell attachment. In this present study, the aim was to improve biocompatibility of PCL microcarrier by introducing oxygen functional group via ultraviolet irradiation and ozone aeration (UV/O3 system) to allow covalent immobilization of gelatin on the PCL microcarrier surface. Respond surface methodology was used as a statistical approach to optimized parameters that effect the immobilization of gelatin. The parameters used to maximized amount of gelatin immobilize were the mol ratio of COOH:EDAC, NHS concentration and gelatin concentration. The optimum conditions for maximum amount of gelatin (1797.33 µg/g) on the surface of PCL were as follows: 1.5 of COOH:EDAC ratio, 10 mM NHS concentration and, 80 mg/ml gelatin. The result shows that gelatin coated PCL microcarrier promote more and rapid cell adhesion with density of  as compared to raw PCL microcarrier (  and UV/O3 treated PCL microcarrier ( . Therefore, immobilization of gelatin with optimized parameters onto PCL microcarrier improved biocompatibility of PCL microcarrier.

scholarly journals New-generation osteoplastic materials based on biological and synthetic matrices

2021 ◽  
Vol 16 (1) ◽  
pp. 36-54
Author(s):  
D. D. Lykoshin ◽  
V. V. Zaitsev ◽  
M. A. Kostromina ◽  
R. S. Esipov
Keyword(s):  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Biologically Active ◽  
Side Reactions ◽  
Prolonged Release ◽  
Pharmaceutical Substances ◽  
Surgical Implants ◽  
Analytical Review ◽  
New Generation

Objectives. The purpose of this analytical review is to evaluate the market for osteoplastic materials and surgical implants, as well as study the features of new-generation materials and the results of clinical applications.Methods. This review summarizes the volumes of research articles presented in the electronic database PubMed and eLIBRARY. A total of 129 scientific articles related to biological systems, calcium phosphate, polymer, and biocomposite matrices as carriers of pharmaceutical substances, primary recombinant protein osteoinductors, antibiotics, and biologically active chemical reagents were analyzed and summarized. The search depth was 10 years.Results. Demineralized bone matrix constitutes 26% of all types of osteoplastic matrices used globally in surgical osteology, which includes neurosurgery, traumatology and orthopedics, dentistry, and maxillofacial and pediatric surgery. Among the matrices, polymer and biocomposite matrices are outstanding. Special attention is paid to the possibility of immobilizing osteogenic factors and target pharmaceutical substances on the scaffold material to achieve controlled and prolonged release at the site of surgical implantation. Polymeric and biocomposite materials can retard the release of pharmaceutical substances at the implantation site, promoting a decrease in the toxicity and an improvement in the therapeutic effect. The use of composite scaffolds of different compositions in vivo results in high osteogenesis, promotes the initialization of biomineralization, and enables the tuning of the degradation rate of the material.Conclusions. Osteoplastic materials of various compositions in combination with drugs showed accelerated regeneration and mineralization of bone tissue in vivo, excluding systemic side reactions. Furthermore, although some materials have already been registered as commercial drugs, a plethora of unresolved problems remain. Due to the limited clinical studies of materials for use on humans, there is still an insufficient understanding of the toxicity of materials, time of their resorption, speed of drug delivery, and the possible long-term adverse effects of using implants of different compositions.

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