Biocompatibility Analyses of HF-Passivated Magnesium Screws for Guided Bone Regeneration (GBR)

Background: Magnesium (Mg) is one of the most promising materials for human use in surgery due to material characteristics such as its elastic modulus as well as its resorbable and regenerative properties. In this study, HF-coated and uncoated novel bioresorbable magnesium fixation screws for maxillofacial and dental surgical applications were investigated in vitro and in vivo to evaluate the biocompatibility of the HF coating. Methods: Mg alloy screws that had either undergone a surface treatment with hydrofluoric-acid (HF) or left untreated were investigated. In vitro investigation included XTT, BrdU and LDH in accordance with the DIN ISO 10993-5/-12. In vivo, the screws were implanted into the tibia of rabbits. After 3 and 6 weeks, degradation, local tissue reactions and bony integration were analyzed histopathologically and histomorphometrically. Additionally, SEM/EDX analysis and synchrotron phase-contrast microtomography (µCT) measurements were conducted. The in vitro analyses revealed that the Mg screws are cytocompatible, with improved results when the surface had been passivated with HF. In vivo, the HF-treated Mg screws implanted showed a reduction in gas formation, slower biodegradation and a better bony integration in comparison to the untreated Mg screws. Histopathologically, the HF-passivated screws induced a layer of macrophages as part of its biodegradation process, whereas the untreated screws caused a slight fibrous tissue reaction. SEM/EDX analysis showed that both screws formed a similar layer of calcium phosphates on their surfaces and were surrounded by bone. Furthermore, the µCT revealed the presence of a metallic core of the screws, a faster absorbing corrosion front and a slow absorbing region of corroded magnesium. Conclusions: Overall, the HF-passivated Mg fixation screws showed significantly better biocompatibility in vitro and in vivo compared to the untreated screws.

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In Vitro Physico-Chemical Characterization and Standardized In Vivo Evaluation of Biocompatibility of a New Synthetic Membrane for Guided Bone Regeneration

Materials ◽

10.3390/ma12071186 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1186

Author(s):

Lívia da Costa Pereira ◽

Carlos Fernando de Almeida Barros Mourão ◽

Adriana Terezinha Neves Novellino Alves ◽

Rodrigo Figueiredo de Brito Resende ◽

Marcelo José Pinheiro Guedes de Uzeda ◽

...

Keyword(s):

Bone Regeneration ◽

Chemical Properties ◽

Chemical Characterization ◽

Guided Bone Regeneration ◽

Tissue Reaction ◽

In Vivo Evaluation ◽

Physico Chemical ◽

Tissue Reactions

This study’s aim was to evaluate the biocompatibility and bioabsorption of a new membrane for guided bone regeneration (polylactic-co-glycolic acid associated with hydroxyapatite and β-tricalcium phosphate) with three thicknesses (200, 500, and 700 µm) implanted in mice subcutaneously. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and the quantification of carbon, hydrogen and nitrogen were used to characterize the physico-chemical properties. One hundred Balb-C mice were divided into 5 experimental groups: Group 1—Sham (without implantation); Group 2—200 μm; Group 3—500 μm; Group 4—700 μm; and Group 5—Pratix®. Each group was subdivided into four experimental periods (7, 30, 60 and 90 days). Samples were collected and processed for histological and histomorphometrical evaluation. The membranes showed no moderate or severe tissue reactions during the experimental periods studied. The 500-μm membrane showed no tissue reaction during any experimental period. The 200-μm membrane began to exhibit fragmentation after 30 days, while the 500-μm and 700-µm membranes began fragmentation at 90 days. All membranes studied were biocompatible and the 500 µm membrane showed the best results for absorption and tissue reaction, indicating its potential for clinical guided bone regeneration.

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In Vitro and In Vivo Surface Reactivity of Various Calcium Phosphate Coatings Deposited Using Electrostatic Spray Deposition (ESD)

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.309-311.607 ◽

2006 ◽

Vol 309-311 ◽

pp. 607-610

Author(s):

Sander C.G. Leeuwenburgh ◽

Joop G.C. Wolke ◽

M.C. Siebers ◽

J. Schoonman ◽

John A. Jansen

Keyword(s):

Calcium Phosphate ◽

Fibrous Tissue ◽

Tissue Response ◽

Specific Chemical ◽

Phosphate Coatings ◽

Time Periods ◽

Tissue Reactions ◽

Calcium Phosphate Coatings

The dissolution and precipitation behavior of various porous, ESD-derived calcium phosphate coatings was investigated a) in vitro after soaking in Simulated Body Fluid (SBF) for several time periods (2, 4, 8, and 12 weeks), and b) in vivo after subcutaneous implantation in the back of goats for identical time periods. At the end of these studies, the physicochemical properties of the coated substrates were characterized by means of Scanning Electron Microscopy (SEM), XRay Diffraction (XRD), Fourier-Transform InfraRed spectroscopy (FTIR) and Energy Dispersive Spectroscopy (EDS). Moreover, part of the implants was prepared for light microscopical evaluation of the tissue response. In vitro, a highly bioactive behavior was observed for all ESD-coatings, characterized by the deposition of a thick and homogeneous carbonate hydroxyapatite precipitation layer on top of the porous coatings. Regarding the in vivo study, no adverse tissue reactions (toxic effects/inflammatory cells) were observed using light microscopy, and all coatings became surrounded by a thin, dense fibrous tissue capsule after implantation. The ESD-coatings degraded gradually at a dissolution rate depending on the specific chemical phase, thereby enabling synthesis of CaP coatings with a tailored degradation rate.

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Insulin Derived Fibrils Induce Cytotoxicity in vitro and Trigger Inflammation in Murine Models

Journal of Diabetes Science and Technology ◽

10.1177/19322968211033868 ◽

2021 ◽

pp. 193229682110338

Author(s):

Brianne E. Lewis ◽

Adam Mulka ◽

Li Mao ◽

Roshanak Sharafieh ◽

Yi Qiao ◽

...

Keyword(s):

Tissue Reaction ◽

Inflammatory Activity ◽

Dependent Diabetes Mellitus ◽

Air Pouch ◽

Tissue Reactions ◽

And Function ◽

Air Pouch Model ◽

Insulin Fibrils

Background: Effective exogenous insulin delivery is the cornerstone of insulin dependent diabetes mellitus management. Recent literature indicates that commercial insulin-induced tissue reaction and cellular cytotoxicity may contribute to variability in blood glucose as well as permanent loss of injection or infusion site architecture and function. It is well accepted that insulin formulations are susceptible to mechanical and chemical stresses that lead to insulin fibril formation. This study aims to characterize in vitro and in vivo toxicity, as well as pro-inflammatory activity of insulin fibrils. Method: In vitro cell culture evaluated cytotoxicity and fibril uptake by macrophages and our modified murine air-pouch model quantified inflammatory activity. The latter employed FLOW cytometry and histopathology to characterize fibril-induced inflammation in vivo, which included fibril uptake by inflammatory phagocytes. Results: These studies demonstrated that insulin derived fibrils are cytotoxic to cells in vitro. Furthermore, inflammation is induced in the murine air-pouch model in vivo and in response, macrophages uptake fibrils both in vitro and in vivo. Conclusions: Administration of insulin fibrils can lead to cytotoxicity in macrophages. In vivo data demonstrate insulin fibrils to be pro-inflammatory which over time can lead to cumulative cell/tissue toxicity, inflammation, and destructive wound healing. Long term, these tissue reactions could contribute to loss of insulin injection site architecture and function.

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The State of the Art and Prospects for Osteoimmunomodulatory Biomaterials

Materials ◽

10.3390/ma14061357 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1357

Author(s):

Andreea-Mariana Negrescu ◽

Anisoara Cimpean

Keyword(s):

Foreign Bodies ◽

Structural Characteristics ◽

Critical Role ◽

Fibrous Tissue ◽

Bioactive Molecules ◽

New Bone Formation ◽

Recent Developments

The critical role of the immune system in host defense against foreign bodies and pathogens has been long recognized. With the introduction of a new field of research called osteoimmunology, the crosstalk between the immune and bone-forming cells has been studied more thoroughly, leading to the conclusion that the two systems are intimately connected through various cytokines, signaling molecules, transcription factors and receptors. The host immune reaction triggered by biomaterial implantation determines the in vivo fate of the implant, either in new bone formation or in fibrous tissue encapsulation. The traditional biomaterial design consisted in fabricating inert biomaterials capable of stimulating osteogenesis; however, inconsistencies between the in vitro and in vivo results were reported. This led to a shift in the development of biomaterials towards implants with osteoimmunomodulatory properties. By endowing the orthopedic biomaterials with favorable osteoimmunomodulatory properties, a desired immune response can be triggered in order to obtain a proper bone regeneration process. In this context, various approaches, such as the modification of chemical/structural characteristics or the incorporation of bioactive molecules, have been employed in order to modulate the crosstalk with the immune cells. The current review provides an overview of recent developments in such applied strategies.

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Local Immune Responses to Chlamydia pneumoniae in the Lungs of BALB/c Mice during Primary Infection and Reinfection

Infection and Immunity ◽

10.1128/iai.66.11.5113-5118.1998 ◽

1998 ◽

Vol 66 (11) ◽

pp. 5113-5118 ◽

Cited By ~ 46

Author(s):

Jenni M. Penttilä ◽

Marjukka Anttila ◽

Mirja Puolakkainen ◽

Aino Laurila ◽

Kari Varkila ◽

...

Keyword(s):

Primary Infection ◽

Bacterial Infections ◽

Chlamydia Pneumoniae ◽

Mononuclear Cells ◽

Relative Increase ◽

Culturable Bacteria ◽

Ifn Γ ◽

Tissue Reactions

ABSTRACT Cell-mediated immune (CMI) responses play a major role in protection as well as pathogenesis of many intracellular bacterial infections. In this study, we evaluated the infection kinetics and assessed histologically the lymphoid reactions and local, in vitro-restimulated CMI responses in lungs of BALB/c mice, during both primary infection and reinfection with Chlamydia pneumoniae. The primary challenge resulted in a self-restricted infection with elimination of culturable bacteria by day 27 after challenge. A mild lymphoid reaction characterized the pathology in the lungs. In vitro CMI responses consisted of a weak proliferative response and no secretion of gamma interferon (IFN-γ). The number of lung-derived mononuclear cells increased substantially during the primary infection; the largest relative increase was observed in B cells (B220+). After reinfection, the number of lung-derived mononuclear cells increased further, and the response consisted mainly of T cells. The reinfection was characterized in vivo by significant protection from infection (fewer cultivable bacteria in the lungs for a shorter period of time) but increased local lymphoid reaction at the infection site. In vitro, as opposed to the response in naive mice, acquired immunity was characterized by a strongly Th1-biased (IFN-γ) CMI response. These results suggest that repeated infections with C. pneumoniae may induce Th1-type responses with similar associated tissue reactions, as shown in C. trachomatis infection models.

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Deciphering the tumor-specific immunopeptidome in vivo with genetically engineered mouse models

10.21203/rs.3.rs-669497/v1 ◽

2021 ◽

Author(s):

Tyler Jacks ◽

Alex Jaeger ◽

Lauren Stopfer ◽

Emma Sanders ◽

Demi Sandel ◽

...

Keyword(s):

Transcript Abundance ◽

Genetically Engineered ◽

Ductal Adenocarcinoma ◽

Affinity Tag ◽

Class I Mhc ◽

Mhc I ◽

Novel Approach ◽

In Vitro Investigation

Abstract Effective immunosurveillance of cancer requires the presentation of peptide antigens on major histocompatibility complex Class I (MHC-I). Recent developments in proteomics have improved the identification of peptides that are naturally presented by MHC-I, collectively known as the “immunopeptidome”. Current approaches to profile tumor immunopeptidomes have been limited to in vitro investigation, which fails to capture the in vivo repertoire of MHC-I peptides, or bulk tumor lysates, which are obscured by the lack of tumor-specific MHC-I isolation. To overcome these limitations, we report here the engineering of a Cre recombinase-inducible affinity tag into the endogenous mouse MHC-I gene and targeting of this allele to the KrasLSL-G12D/+; p53fl/fl (KP) mouse model (KP; KbStrep). This novel approach has allowed us to isolate tumor-specific MHC-I peptides from autochthonous pancreatic ductal adenocarcinoma (PDAC) and lung adenocarcinoma (LUAD) in vivo. With this powerful analytical tool, we were able to profile the evolution of the LUAD immunopeptidome through tumor progression and show that in vivo MHC-I presentation is shaped by post-translational mechanisms. We also uncovered novel, putative LUAD tumor associated antigens (TAAs). Many peptides that were recurrently presented in vivo exhibited very low expression of the cognate mRNA, provoking reconsideration of antigen prediction pipelines that triage peptides according to transcript abundance. Beyond cancer, the KbStrep allele is compatible with a broad range of Cre-driver lines to explore antigen presentation in vivo in the pursuit of understanding basic immunology, infectious disease, and autoimmunity.

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A Comparative Study of Bioceramics In Vitro and In Vivo

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.284-286.11 ◽

2005 ◽

Vol 284-286 ◽

pp. 11-14 ◽

Cited By ~ 2

Author(s):

Yang Leng ◽

Ren Long Xin ◽

Ji Yong Chen

Keyword(s):

Calcium Phosphates ◽

Glass Ceramics ◽

Octacalcium Phosphate ◽

Rabbit Muscle ◽

In Vivo Experiments ◽

Transmission Electron ◽

Diffraction Patterns ◽

Dental Applications

Bioactive calcium phosphate (Ca-P) formation in bioceramics surfaces in simulated body fluid (SBF) and in rabbit muscle sites was investigated. The examined bioceamics included most commonly used bioglass®, A-W glass-ceramics and calcium phosphates in orthopedic and dental applications. The Ca-P cyrstal structures were examined with single crystal diffraction patterns in transmission electron microscopy, which reduced possibility of misidentifying Ca-P phases. The experimental results show that capability of Ca-P formation considerably varied among bioceramics, particularly in vivo. Octacalcium phosphate (OCP) was revealed on the all types of bioceramics in vitro and in vivo experiments. This work leads us to rethink how to evaluate bioactivity of bioceramics and other orthopedic materials which exhibit capability of osteoconduction by forming direct bonding with bone.

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Osseoinduction Evaluation of Hydroxyapatite and Zinc Containing Hydroxyapatite Granules in Rabbits

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.493-494.252 ◽

2011 ◽

Vol 493-494 ◽

pp. 252-257 ◽

Cited By ~ 1

Author(s):

L. Nascimento ◽

M. Medeiros ◽

J. Calasans-Maia ◽

A. Alves ◽

Antonella M. Rossi ◽

...

Keyword(s):

Histological Analysis ◽

Bone Matrix ◽

Fibrous Tissue ◽

Particle Diameter ◽

Inflammatory Cells ◽

Giant Cells ◽

Multinucleated Giant Cells ◽

Ethics Commission

This study investigated the osteoinductive potential of granules of stoichiometric hydroxyapatite (HA) and 0.5% zinc containing hydroxyapatite (ZnHA) in intramuscular (IM) site of rabbit’s abdomen. The biomaterials were both used in granular form, with 75% porosity and particle diameter between 450 and 500μm, sintered at 1100°C. Both materials performed adequately on a multiparametric in vitro cytocompatibility assay, indicating their suitability for in vivo testing. After approval by the Ethics Commission on Teaching and Research in Animals, fifteen rabbits were submitted to general anesthesia, incision and tissue dilatation, and a small site was created for HA (right incision) and ZnHA (left incision) intramuscular implantation. The animals were killed after 2, 4 and 12 weeks for biomaterials and surrounding tissues removal. Histological analysis after 2 weeks revealed the presence of granulation tissue surrounding biomaterials with multinucleated giant cells and no newly formed bone for both materials. After 4 weeks there was fibrous tissue involving the material and few inflammatory cells. Following 12 weeks it was observed the presence of connective tissue surrounding the biomaterial, cellularized enough for the two experimental groups, but it was not observed the presence of bone matrix associated with the biomaterials. We conclude that both biomaterials are cytocompatible and did not present the property of osseoinduction after 12 weeks of implantation.

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Natural Poly(Hydroxybutyrate-Hydroxyvalerate) Polymers as Degradable Biomatertals.

MRS Proceedings ◽

10.1557/proc-394-111 ◽

1995 ◽

Vol 394 ◽

Cited By ~ 8

Author(s):

Cyril Chaput ◽

L'Hocine Yahia ◽

Amine Selmani ◽

Charles-Hilaire Rivard

Keyword(s):

Copolymer Composition ◽

Inflammatory Reactions ◽

Accelerated Degradation ◽

Physico Chemical ◽

Degradation Rates ◽

Degradable Biomaterials ◽

Tissue Reactions ◽

Toxic Responses

AbstractPoly(ß-hydroxybutyrate-co-13-hydroxyvalerate) have been recently proposed as degradable biomaterials for drug delivery systems, sutures, bone plates and short-term implants. Three P-B\HV (7, 14 & 22 % HV) films were analyzed for in vitro cytotoxicity and aqueous accelerated degradation, in vivo degradation and tissue reactions. The PHB/HV materials and extracts elicit few or mild toxic responses, do not lead in vivo to tissue necrosis or abscess formation, but provoke acute inflammatory reactions slightly decreasing with the time. The degradation of PHB/HV polymers present low rates in vitro as well as in vivo. The weight loss rate generally increases with the copolymer composition (HV content) and ranges from 0.15- 0.30 (in vitro) to 0.25 %/day (in vivo). Compositional and physico-chemical changes in PHB/HV materials were rapidly detected during the accelerated hydrolysis, but were much slower to appear in vivo. The structural and mechanical integrity of PHB/HV materials tend to disappear early in vitro as well as in vivo. After 90 wks in dorsal muscular tissues of adult sheep, there was no significant dissolution of the PHB/HV polymer, 50–60% of the initial weight still remaining. PHB/HV polymers are biodegradable materials, either by hydrolysis or implantation, but with extremely low dissolution or degradation rates.

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Infrared Spectroscopy with a Fiber-Coupled Quantum Cascade Laser for Attenuated Total Reflection Measurements Towards Biomedical Applications

Sensors ◽

10.3390/s19235130 ◽

2019 ◽

Vol 19 (23) ◽

pp. 5130 ◽

Cited By ~ 3

Author(s):

Ine L. Jernelv ◽

Karina Strøm ◽

Dag Roar Hjelme ◽

Astrid Aksnes

Keyword(s):

Infrared Spectroscopy ◽

Quantum Cascade Lasers ◽

Spectral Power ◽

Total Reflection ◽

Attenuated Total Reflection ◽

Mid Infrared ◽

Quantum Cascade ◽

In Vitro Investigation

The development of rapid and accurate biomedical laser spectroscopy systems in the mid-infrared has been enabled by the commercial availability of external-cavity quantum cascade lasers (EC-QCLs). EC-QCLs are a preferable alternative to benchtop instruments such as Fourier transform infrared spectrometers for sensor development as they are small and have high spectral power density. They also allow for the investigation of multiple analytes due to their broad tuneability and through the use of multivariate analysis. This article presents an in vitro investigation with two fiber-coupled measurement setups based on attenuated total reflection spectroscopy and direct transmission spectroscopy for sensing. A pulsed EC-QCL (1200–900 cm − 1 ) was used for measurements of glucose and albumin in aqueous solutions, with lactate and urea as interferents. This analyte composition was chosen as an example of a complex aqueous solution with relevance for biomedical sensors. Glucose concentrations were determined in both setup types with root-mean-square error of cross-validation (RMSECV) of less than 20 mg/dL using partial least-squares (PLS) regression. These results demonstrate accurate analyte measurements, and are promising for further development of fiber-coupled, miniaturised in vivo sensors based on mid-infrared spectroscopy.

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