Tunability of collagen matrix mechanical properties via multiple modes of mineralization

Functionally graded, mineralized collagen tissues exist at soft-to-hard material attachments throughout the body. However, the details of how collagen and hydroxyapatite mineral (HA) interact are not fully understood, hampering efforts to develop tissue-engineered constructs that can assist with repair of injuries at the attachments of soft tissues to bone. In this study, spatial control of mineralization was achieved in collagen matrices using simulated body fluids (SBFs). Based upon previous observations of poor bonding between reconstituted collagen and HA deposited using SBF, we hypothesized that mineralizing collagen in the presence of fetuin (which inhibits surface mineralization) would lead to more mineral deposition within the scaffold and therefore a greater increase in stiffness and toughness compared with collagen mineralized without fetuin. We tested this hypothesis through integrated synthesis, mechanical testing and modelling of graded, mineralized reconstituted collagen constructs. Results supported the hypothesis, and further suggested that mineralization on the interior of reconstituted collagen constructs, as promoted by fetuin, led to superior bonding between HA and collagen. The results provide us guidance for the development of mineralized collagen scaffolds, with implications for bone and tendon-to-bone tissue engineering.

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MECHANICAL BEHAVIOR UNDER UNCONFINED COMPRESSION LOADINGS OF DENSE FIBRILLAR COLLAGEN MATRICES MIMETIC OF LIVING TISSUES

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519410003290 ◽

2010 ◽

Vol 10 (01) ◽

pp. 35-55 ◽

Cited By ~ 12

Author(s):

SALAH RAMTANI ◽

YOSHIYUKI TAKAHASHI-IÑIGUEZ ◽

CHRISTOPHE HELARY ◽

DIDIER GEIGER ◽

MARIE MADELEINE GIRAUD GUILLE

Keyword(s):

Mechanical Properties ◽

Soft Tissues ◽

Three Dimensional ◽

Fibrillar Collagen ◽

Unconfined Compression ◽

Collagen Scaffolds ◽

Collagen Concentration ◽

Collagen Matrices ◽

Compression Load ◽

Living Tissues

Bio-artificial tissues are being developed as replacements for damaged biologic tissues and their mechanical properties are critical for load-bearing applications. Reconstituted dense three-dimensional (3D) fibrillar collagen matrices are promising materials for tissue engineering, at the light of their interaction with fibroblasts.1,2 The mechanical properties of these fibrillar collagen matrices are now being characterized under unconfined compression loading for various strain rates and collagen concentrations. The data were compared to those obtained in the same conditions with a biological tissue, the rat dermis. The results show a very sensitive behavior to both the displacement rate, typical of biological soft tissues, and the collagen concentration varying between 5 and 40 mg/ml. The link between the mechanical properties and the microscopic structure of the collagen scaffolds show an increasing viscoelastic modulus with respect to the fibril density. It is found that the matrices at 5 mg/ml and the dorsal rat skin (DRS) exhibit similar stress–strain response when submitted to the same external unconfined compression load. Such results highlight the interest of these matrices as potential tissue substitutes.

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Mineralized collagen scaffolds fabricated with amniotic membrane matrix increase osteogenesis under inflammatory conditions

10.1101/2020.01.23.917443 ◽

2020 ◽

Author(s):

Marley J. Dewey ◽

Eileen M. Johnson ◽

Simona T. Slater ◽

Derek J. Milner ◽

Matthew B. Wheeler ◽

...

Keyword(s):

Osteogenic Differentiation ◽

Amniotic Membrane ◽

Bone Repair ◽

Composite Scaffold ◽

High Energy ◽

Collagen Scaffolds ◽

Membrane Matrix ◽

Inflammatory Conditions ◽

Mineral Deposition ◽

Mineralized Collagen

ABSTRACTDefects in craniofacial bones occur congenitally, after high-energy impacts, and during the course of treatment for stroke and cancer. These injuries are difficult to heal due to the overwhelming size of the injury area and the inflammatory environment surrounding the injury. Significant inflammatory response after injury may greatly inhibit regenerative healing. We have developed mineralized collagen scaffolds that can induce osteogenic differentiation and matrix biosynthesis in the absence of osteogenic media or supplemental proteins. The amniotic membrane is derived from placentas and has been recently investigated as an extracellular matrix to prevent chronic inflammation. Herein, we hypothesized that a mineralized collagen-amnion composite scaffold could increase osteogenic activity in the presence of inflammatory cytokines. We report mechanical properties of a mineralized collagen-amnion scaffold and investigated osteogenic differentiation and mineral deposition of porcine adipose derived stem cells within these scaffolds as a function of inflammatory challenge. Incorporation of amniotic membrane matrix promotes osteogenesis similarly to un-modified mineralized collagen scaffolds, and increases in mineralized collagen-amnion scaffolds under inflammatory challenge. Together, these findings suggest that a mineralized collagen-amnion scaffold may provide a beneficial environment to aid craniomaxillofacial bone repair, especially in the course of defects presenting significant inflammatory complications.

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Buccal Peri-Implant Soft Tissue Augmentation by Means of a Porcine Collagen Matrix: A Proof of Concept Technical Note

Materials ◽

10.3390/ma14010093 ◽

2020 ◽

Vol 14 (1) ◽

pp. 93

Author(s):

Mario Beretta ◽

Carlo Maiorana ◽

Mattia Manfredini ◽

Susanna Ferrario ◽

Pier Paolo Poli

Keyword(s):

Soft Tissue ◽

Soft Tissues ◽

Present Report ◽

Collagen Matrix ◽

Technical Note ◽

Soft Tissue Augmentation ◽

Collagen Matrices ◽

Mucosal Thickness ◽

Tissue Grafts ◽

Porcine Collagen

The quality and quantity of peri-implant soft tissues at the crestal portion of dental implants are important aspects to consider for a long-term successful implant-supported rehabilitation. Some relevant factors attributed to the implant health include mucosal thickness and keratinization. In this respect, many techniques and materials have been described to augment and improve buccal peri-implant soft tissues. Over the last few years, newly developed xenogeneic collagen matrices have been introduced in peri-implant plastic surgery to replace autogenous soft tissue grafts; however, data remain controversial so far. Thus, the purpose of the present report was to present a novel surgical technique conceived to augment buccal peri-implant soft tissues in combination with a volume-stable porcine collagen matrix. The rationale and the fundamental concepts that led to the use of a xenogeneic matrix to increase soft tissue volumes were also discussed.

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Functional Grading of a Transversely Isotropic Hyperelastic Model with Applications in Modeling Tricuspid and Mitral Valve Transition Regions

International Journal of Molecular Sciences ◽

10.3390/ijms21186503 ◽

2020 ◽

Vol 21 (18) ◽

pp. 6503

Author(s):

Rajarshi Roy ◽

Eric Warren ◽

Yaoyao Xu ◽

Caleb Yow ◽

Rama S. Madhurapantula ◽

...

Keyword(s):

Mitral Valve ◽

Soft Tissues ◽

Transversely Isotropic ◽

Biological Tissues ◽

Functionally Graded ◽

The Body ◽

Research Attention ◽

Graded Material ◽

Diffraction Imaging ◽

Tissue Geometry

Surgical simulators and injury-prediction human models require a combination of representative tissue geometry and accurate tissue material properties to predict realistic tool–tissue interaction forces and injury mechanisms, respectively. While biological tissues have been individually characterized, the transition regions between tissues have received limited research attention, potentially resulting in inaccuracies within simulations. In this work, an approach to characterize the transition regions in transversely isotropic (TI) soft tissues using functionally graded material (FGM) modeling is presented. The effect of nonlinearities and multi-regime nature of the TI model on the functional grading process is discussed. The proposed approach has been implemented to characterize the transition regions in the leaflet (LL), chordae tendinae (CT) and the papillary muscle (PM) of porcine tricuspid valve (TV) and mitral valve (MV). The FGM model is informed using high resolution morphological measurements of the collagen fiber orientation and tissue composition in the transition regions, and deformation characteristics predicted by the FGM model are numerically validated to experimental data using X-ray diffraction imaging. The results indicate feasibility of using the FGM approach in modeling soft-tissue transitions and has implications in improving physical representation of tissue deformation throughout the body using a scalable version of the proposed approach.

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Mineralized collagen scaffolds fabricated with amniotic membrane matrix increase osteogenesis under inflammatory conditions

Regenerative Biomaterials ◽

10.1093/rb/rbaa005 ◽

2020 ◽

Vol 7 (3) ◽

pp. 247-258

Author(s):

Marley J Dewey ◽

Eileen M Johnson ◽

Simona T Slater ◽

Derek J Milner ◽

Matthew B Wheeler ◽

...

Keyword(s):

Osteogenic Differentiation ◽

Amniotic Membrane ◽

Bone Repair ◽

Composite Scaffold ◽

High Energy ◽

Collagen Scaffolds ◽

Membrane Matrix ◽

Inflammatory Conditions ◽

Mineral Deposition ◽

Mineralized Collagen

Abstract Defects in craniofacial bones occur congenitally, after high-energy impacts, and during the course of treatment for stroke and cancer. These injuries are difficult to heal due to the overwhelming size of the injury area and the inflammatory environment surrounding the injury. Significant inflammatory response after injury may greatly inhibit regenerative healing. We have developed mineralized collagen scaffolds that can induce osteogenic differentiation and matrix biosynthesis in the absence of osteogenic media or supplemental proteins. The amniotic membrane is derived from placentas and has been recently investigated as an extracellular matrix to prevent chronic inflammation. Herein, we hypothesized that a mineralized collagen–amnion composite scaffold could increase osteogenic activity in the presence of inflammatory cytokines. We report mechanical properties of a mineralized collagen–amnion scaffold and investigated osteogenic differentiation and mineral deposition of porcine adipose-derived stem cells within these scaffolds as a function of inflammatory challenge. Incorporation of amniotic membrane matrix promotes osteogenesis similarly to un-modified mineralized collagen scaffolds, and increases in mineralized collagen–amnion scaffolds under inflammatory challenge. Together, these findings suggest that a mineralized collagen–amnion scaffold may provide a beneficial environment to aid craniomaxillofacial bone repair, especially in the course of defects presenting significant inflammatory complications.

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Chemotactic and Angiogenic Potential of Mineralized Collagen Scaffolds Functionalized with Naturally Occurring Bioactive Factor Mixtures to Stimulate Bone Regeneration

International Journal of Molecular Sciences ◽

10.3390/ijms22115836 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5836

Author(s):

Henriette Bretschneider ◽

Mandy Quade ◽

Anja Lode ◽

Michael Gelinsky ◽

Stefan Rammelt ◽

...

Keyword(s):

Bone Marrow ◽

Platelet Rich Plasma ◽

Umbilical Vein ◽

Release Kinetics ◽

Human Bone ◽

Human Bone Marrow ◽

Collagen Scaffolds ◽

Angiogenic Potential ◽

Naturally Occurring ◽

Mineralized Collagen

To develop cost-effective and efficient bone substitutes for improved regeneration of bone defects, heparin-modified mineralized collagen scaffolds were functionalized with concentrated, naturally occurring bioactive factor mixtures derived from adipose tissue, platelet-rich plasma and conditioned medium from a hypoxia-treated human bone marrow-derived mesenchymal stem cell line. Besides the analysis of the release kinetics of functionalized scaffolds, the bioactivity of the released bioactive factors was tested with regard to chemotaxis and angiogenic tube formation. Additionally, functionalized scaffolds were seeded with human bone marrow-derived mesenchymal stromal cells (hBM-MSC) and their osteogenic and angiogenic potential was investigated. The release of bioactive factors from the scaffolds was highest within the first 3 days. Bioactivity of the released factors could be confirmed for all bioactive factor mixtures by successful chemoattraction of hBM-MSC in a transwell assay as well as by the formation of prevascular structures in a 2D co-culture system of hBM-MSC and human umbilical vein endothelial cells. The cells seeded directly onto the functionalized scaffolds were able to express osteogenic markers and form tubular networks. In conclusion, heparin-modified mineralized collagen scaffolds could be successfully functionalized with naturally occurring bioactive factor mixtures promoting cell migration and vascularization.

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Magnetic Resonance Imaging in the Diagnosis of Disruption of the Posterior Tibial Tendon

Foot & Ankle ◽

10.1177/107110078700800307 ◽

1987 ◽

Vol 8 (3) ◽

pp. 144-147 ◽

Cited By ~ 26

Author(s):

Ian J. Alexander ◽

Kenneth A. Johnson ◽

Thomas H. Berquist

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Soft Tissues ◽

Diagnostic Technique ◽

Clinical Findings ◽

The Body ◽

Posterior Tibial Tendon ◽

Resonance Imaging ◽

Posterior Tibial ◽

Magnetic Resonance Imaging Mri

Magnetic resonance imaging (MRI), a useful technique of studying soft tissues of the body, can be very effective in assessing the integrity of tendons. Usually a patient with a complete tear of the posterior tibial tendon has characteristic physical findings. In the patient presented, MRI demonstrated a complete disruption of the posterior tibial tendon, despite the absence of the commonly associated clinical findings. In view of the difficulties encountered with attempted tenography of the completely torn posterior tibial tendon, MRI provides a sensitive alternative diagnostic technique.

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Computerized Tomography: A Perspective in the Pediatric Patient

PEDIATRICS ◽

10.1542/peds.59.2.305 ◽

1977 ◽

Vol 59 (2) ◽

pp. 305-308

Author(s):

Derek Harwood-Nash ◽

Herman Grossman ◽

Alvin Felman ◽

John Kirkpatrick ◽

Leonard Swischuk

Keyword(s):

Computerized Tomography ◽

Soft Tissues ◽

Conventional Radiography ◽

The United States ◽

The Body ◽

Whole Body ◽

Central Research ◽

X Ray ◽

Whole Body Ct

Computerized tomography (CT), a technique conceptualized by Oldendorf in 19611 and developed by Hounsfield2 of EMI-Tronics Inc. (EMI) Central Research Laboratories, has proven to be a successful innovation in neuroradiology. Reviews by Ambrose3 in England and by Baker et al.4 and by New et al.5 in the United States have clearly demonstrated the value of this new modality in neuroradiological diagnosis. In 1975 Houser et al.6 and Harwood-Nash et al.7 provided the initial clinical and radiological data about CT in infants and children. More recently this technique has been extended to the study of tissues and organs in the body other than those in the head. This has been accomplished by modification of the original machine into a whole-body CT system. Early reviews by Ledley et al.8 and by Alfidi et al.9 suggest a significant potential for diagnosis of lesions in the abdomen, pelvis, and thorax. The advantages of CT are that it is less invasive than standard special diagnostic radiological procedures and that for the first time it provides in vivo information regarding the content and the characteristics of tissue composing organs and masses. DESCRIPTION OF EQUIPMENT In conventional radiography an image is made on radiographic film by an attenuated X-ray beam. In passing through a core of tissue, each ray of the beam is attenuated as it is absorbed and scattered by the tissue in its path. The intensity of the transmitted ray depends on the sum total of X-ray attenuation by all the different soft tissues in its path.

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The reaction of the soft tissues of the anterior abdominal wall to various suture material

Kazan medical journal ◽

10.17816/kazmj62327 ◽

1982 ◽

Vol 63 (4) ◽

pp. 72-74

Author(s):

V. P. Nefedov ◽

R. M. Ramazanov

Keyword(s):

Foreign Body ◽

Abdominal Wall ◽

Soft Tissues ◽

Suture Material ◽

Anterior Abdominal Wall ◽

The Body ◽

Reactive Changes ◽

Healing Processes

The healing processes of sutured wounds of soft tissues in most cases depend on the type and quality of the suture material. Any kind of suture material in the tissues of the body is a foreign body that causes various reactive changes from the tissues. The nature of these changes, all other things being equal, is mainly determined by the type of suture material, its thickness and the method of sterilization of the tissues on which the sutures are applied, the trauma of surgery, the infection of the wound and the irritating effect of the threads on the tissues.

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Initial Results On Medium Frequency Electromagnetic Field Penetration In Biological Soft Tissue

Jurnal Teknologi ◽

10.11113/jt.v54.802 ◽

2012 ◽

Cited By ~ 1

Author(s):

Zulkarnay Zakaria ◽

Mohd Fahajumi Jumaah ◽

Mohd Saiful Badri Mansor ◽

Khairi Mat Daud ◽

Mohd Hafiz Fazalul Rahiman ◽

...

Keyword(s):

Magnetic Field ◽

Soft Tissue ◽

Soft Tissues ◽

Low Cost ◽

The Body ◽

Small Scale ◽

Medium Frequency ◽

Magnetic Field Penetration ◽

Magnetic Induction Tomography ◽

Field Penetration

Terapi merupakan antara teknik perubatan tertua dalam mengekalkan kesihatan badan terutama daripada aliran darah yang tidak baik, strok dan beberapa penyakit yang lain. Teknik ini termasuklah akupuntur, guasa dan juga urutan. Terdapat juga teknik terapi moden seperti terapi warna, terapi ozon, terapi dadah dan banyak lagi. Kertas kajian ini akan mengetengahkan penjana terapi elektromagnet, satu alat yang mempunyai potensi aplikasi terapi dalam bidang perubatan. Alat ini menghasilkan medan magnet berfrekuensi sederhana sebagai sumber terapi. Perkakasan yang berskala kecil berfrekuensi sederhana dan berkos rendah ini telah dibangunkan dan telah diuji pada tisu biologi bagi mengukur tahap ketembusan medan magnet. Ujian ini telah membuktikan bahawa medan magnet yang telah dihasilkan mampu menembusi tisu lembut bersaiz sehingga 2 cm dengan jarak 7 cm daripada sumber. Kebolehan penembusan sistem ini terhadap tisu lembut memberikan peluang yang cerah kepada kajian ini memandangkan medan magnet telah menunjukkan potensi sebagai sebahagian daripada terapi untuk memulihkan migraine, strok, kekejangan dan beberapa yang lain selain boleh diaplikasikan dalam pengimejan tomografi induksi magnet. Kata kunci: Terapi elektromagnet, medan magnet, penembusan, tisu lembut, aplikasi perubatan Therapy is among the oldest medication technique in maintaining the health of the body especially from bad blood circulation, stroke and several others. This technique includes acupuncture, guasa and also massage. There are also modern therapy techniques like colour therapy, water therapy, ozone therapy, drug therapy and others. This paper will highlight electromagnetic therapy generator, a device which has the potential of therapy application in medical field. This device produce medium frequency magnetic field as a therapy source. This small scale medium frequency and low cost hardware that has been developed was tested on the biological tissue for the purpose of measuring the magnetic field penetration. The testing has proven that the generated magnetic field is able to penetrate the soft tissue up to 2 cm with distance from the source up to 7 cm. The capability of the system penetrations through the soft tissues provide the bright future of this research since magnetic field have shown the potential as being part of the therapy for curing migraine, stroke, cramp and several others besides the application in the magnetic induction tomography imaging. Key words: Electromagnetic therapy, magnetic field, penetration, soft tissue; medical applications

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