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Träfflista för sökning "WFRF:(Chodosh James) ;pers:(Nilsson Per H. 1980)"

Sökning: WFRF:(Chodosh James) > Nilsson Per H. 1980

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1.
  • Islam, Mohammad Mirazul, et al. (författare)
  • Effects of gamma radiation sterilization on the structural and biological properties of decellularized corneal xenografts
  • 2019
  • Ingår i: Acta Biomaterialia. - : Elsevier. - 1742-7061 .- 1878-7568. ; 96, s. 330-344
  • Tidskriftsartikel (refereegranskat)abstract
    • To address the shortcomings associated with corneal transplants, substantial efforts have been focused on developing new modalities such as xenotransplantion. Xenogeneic corneas are anatomically and biomechanically similar to the human cornea, yet their applications require prior decellularization to remove the antigenic components to avoid rejection. In the context of bringing decellularized corneas into clinical use, sterilization is a crucial step that determines the success of the transplantation. Well-standardized sterilization methods, such as gamma irradiation (GI), have been applied to decellularized porcine corneas (DPC) to avoid graft-associated infections in human recipients. However, little is known about the effect of GI on decellularized corneal xenografts. Here, we evaluated the radiation effect on the ultrastructure, optical, mechanical and biological properties of DPC. Transmission electron microscopy revealed that gamma irradiated decellularized porcine cornea (G-DPC) preserved its structural integrity. Moreover, the radiation did not reduce the optical properties of the tissue. Neither DPC nor G-DPC led to further activation of complement system compared to native porcine cornea when exposed to plasma. Although, DPC were mechanically comparable to the native tissue, GI increased the mechanical strength, tissue hydrophobicity and resistance to enzymatic degradation. Despite these changes, human corneal epithelial, stromal, endothelial and hybrid neuroblastoma cells grew and differentiated on DPC and G-DPC. Thus, GI may achieve effective tissue sterilization without affecting critical properties that are essential for corneal transplant survival. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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2.
  • Islam, Rakibul, et al. (författare)
  • Combined blockade of complement C5 and TLR co-receptor CD14 synergistically inhibits pig-to-human corneal xenograft induced innate inflammatory responses
  • 2021
  • Ingår i: Acta Biomaterialia. - : Elsevier. - 1742-7061 .- 1878-7568. ; 127, s. 169-179
  • Tidskriftsartikel (refereegranskat)abstract
    • Inadequate supplies of donor corneas have evoked an escalating interest in corneal xenotransplantation. However, innate immune responses contribute significantly to the mechanism of xenograft rejection. We hypothesized that complement component C5 and TLR co-receptor CD14 inhibition would inhibit porcine cornea induced innate immune responses. Therefore, we measured cytokine release in human blood, induced by three forms of corneal xenografts with or without inhibitors. Native porcine cornea (NPC) induced interleukins (IL-1 beta, IL-2, IL-6, IL-8, IL-1ra), chemokines (MCP-1, MIP-1 alpha, MIP-1 beta) and other cytokines (TNF, G-CSF, INF-gamma, FGF-basic). Decellularized (DPC) and gamma-irradiated cornea (g-DPC) elevated the release of those cytokines. C5-blockade by eculizumab inhibited all the cytokines except G-CSF when induced by NPC. However, C5-blockade failed to reduce DPC and g-DPC induced cytokines. Blockade of CD14 inhibited DPC-induced cytokines except for IL-8, MCP-1, MIP-1 alpha, and G-CSF, while it inhibited all of them when induced by g-DPC. Combined blockade of C5 and CD14 inhibited the maximum number of cytokines regardless of the xenograft type. Finally, by using the TLR4 specific inhibitor Eritoran, we showed that TLR4 activation was the basis for the CD14 effect. Thus, blockade of C5, when combined with TLR4 inhibition, may have therapeutic potential in pig-to-human corneal xenotransplantation. Statement of significance Bio-engineered corneal xenografts are on the verge of becoming a viable alternative to allogenic human donor-cornea, but the host's innate immune response is still a critical barrier for graft acceptance. By overruling this barrier, limited graft availability would no longer be an issue for treating corneal diseases. We showed that the xenograft induced inflammation is initiated by the complement system and toll-like receptor activation. Intriguingly, the inflammatory response was efficiently blocked by simultaneously targeting bottleneck molecules in the complement system (C5) and the TLR co-receptor CD14 with pharmaceutical inhibitors. We postulate that a combination of C5 and CD14 inhibition could have a great therapeutic potential to overcome the immunologic barrier in pig-to-human corneal xenotransplantation. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc.
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3.
  • Sharifi, Sina, et al. (författare)
  • Electron Beam Sterilization of Poly(Methyl Methacrylate)-Physicochemical and Biological Aspects
  • 2021
  • Ingår i: Macromolecular Bioscience. - : John Wiley & Sons. - 1616-5187 .- 1616-5195. ; 21:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Electron beam (E-beam) irradiation is an attractive and efficient method for sterilizing clinically implantable medical devices made of natural and/or synthetic materials such as poly(methyl methacrylate) (PMMA). As ionizing irradiation can affect the physicochemical properties of PMMA, understanding the consequences of E-beam sterilization on the intrinsic properties of PMMA is vital for clinical implementation. A detailed assessment of the chemical, optical, mechanical, morphological, and biological properties of medical-grade PMMA after E-beam sterilization at 25 and 50 kiloGray (kGy) is reported. Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry studies indicate that E-beam irradiation has minimal effect on the chemical properties of the PMMA at these doses. While 25 kGy irradiation does not alter the mechanical and optical properties of the PMMA, 50 kGy reduces the flexural strength and transparency by 10% and 2%, respectively. Atomic force microscopy demonstrates that E-beam irradiation reduces the surface roughness of PMMA in a dose dependent manner. Live-Dead, AlamarBlue, immunocytochemistry, and complement activation studies show that E-beam irradiation up to 50 kGy has no adverse effect on the biocompatibility of the PMMA. These findings suggest that E-beam irradiation at 25 kGy may be a safe and efficient alternative for PMMA sterilization.
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4.
  • Sharifi, Sina, et al. (författare)
  • Sputter Deposition of Titanium on Poly(Methyl Methacrylate) Enhances Corneal Biocompatibility
  • 2020
  • Ingår i: Translational Vision Science & Technology. - : Association for Research in Vision and Ophthalmology. - 2164-2591. ; 9:13, s. 1-14
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To evaluate titanium (Ti) sputtering of the poly(methyl methacrylate) (PMMA) stem of the Boston Keratoprosthesis (BK) as a method to enhance interfacial adhesion between the PMMA and the recipient corneal tissue. Methods: PMMA specimens were plasma treated with Ar/O-2 and coated with Ti using a DC magnetron sputtering instrument. The topography and hydrophilicity of the surfaces were characterized using atomic force microscopy and a water contact angle instrument, respectively. Scratch hardness and adhesion of the Ti film were measured using a mechanical tester. Biocompatibility assessments were performed using cultured human corneal fibroblasts and whole blood ex vivo. The optical quality of the Ti sputtered BK was evaluated using a custom-made optical bench. Results: By contact angle studies, the Ti coating improved PMMA hydrophilicity to match that of medical-grade Ti (Ti-6Al-4V-ELI). Ti sputtering of contact surfaces resulted in a plate-like morphology with increased surface roughness, without impacting the transparency of the BK optical component. Scratch testing indicated that the mechanical behavior of the Ti coating was similar to that of casted Ti, and the coating was stable in pull-off adhesion testing. Sputtered Ti film was highly biocompatible based on tests of cell viability, adhesion, proliferation, differentiation, collagen deposition, and keratocan expression, the properties of which exceeded those of uncoated PMMA and did not induce increased complement activation. Conclusions: Titanium coating of the BK stem generated a mechanically and biologically favorable interface, which may help to enhance corneal stromal adhesion and biocompatibility. Translational Relevance: Improving the biocompatibility of the BK PMMA stem may improve long-term outcomes of implantation.
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5.
  • Sharifi, Sina, et al. (författare)
  • Tuning gelatin-based hydrogel towards bioadhesive ocular tissue engineering applications
  • 2021
  • Ingår i: Bioactive Materials. - : Elsevier. - 2452-199X. ; 6:11, s. 3947-3961
  • Tidskriftsartikel (refereegranskat)abstract
    • Gelatin based adhesives have been used in the last decades in different biomedical applications due to the excellent biocompatibility, easy processability, transparency, non-toxicity, and reasonable mechanical properties to mimic the extracellular matrix (ECM). Gelatin adhesives can be easily tuned to gain different viscoelastic and mechanical properties that facilitate its ocular application. We herein grafted glycidyl methacrylate on the gelatin backbone with a simple chemical modification of the precursor, utilizing epoxide ring-opening reactions and visible light-crosslinking. This chemical modification allows the obtaining of an elastic protein-based hydrogel (GELGYM) with excellent biomimetic properties, approaching those of the native tissue. GELGYM can be modulated to be stretched up to 4 times its initial length and withstand high tensile stresses up to 1.95 MPa with compressive strains as high as 80% compared to Gelatin-methacryloyl (GeIMA), the most studied derivative of gelatin used as a bioadhesive. GELGYM is also highly biocompatible and supports cellular adhesion, proliferation, and migration in both 2 and 3-dimensional cell-cultures. These characteristics along with its super adhesion to biological tissues such as cornea, aorta, heart, muscle, kidney, liver, and spleen suggest widespread applications of this hydrogel in many biomedical areas such as transplantation, tissue adhesive, wound dressing, bioprinting, and drug and cell delivery.
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