| 1. |
- Chen, Yue, et al.
(författare)
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A novel nanoparticle system targeting damaged mitochondria for the treatment of Parkinson's disease
- 2022
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Ingår i: Biomaterials Advances. - : Elsevier BV. - 2772-9516 .- 2772-9508. ; 138
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial damage is one of the primary causes of neuronal cell death in Parkinson's disease (PD). In PD patients, the mitochondrial damage can be repaired or irreversible. Therefore, mitochondrial damage repair becomes a promising strategy for PD treatment. In this research, hyaluronic acid nanoparticles (HA-NPs) of different molecular weights are used to protect the mitochondria and salvage the mild and limited damage in mitochondria. The HA-NPs with 2190 k Dalton (kDa) HA can improve the mitochondrial function of SH-SY5Y cells and PTEN induced putative kinase 1 (PINK1) knockout mouse embryo fibroblast (MEF) cells. In cases of irreversible damage, NPs with ubiquitin specific peptidase 30 (USP30) siRNA are used to promote mitophagy. Meanwhile, by adding PINK1 antibodies, the NPs can selectively target the irreversibly damaged mitochondria, preventing the excessive clearance of healthy mitochondria.
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| 2. |
- Diez-Escudero, Anna, et al.
(författare)
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3D-printed porous Ti6Al4V alloys with silver coating combine osteocompatibility and antimicrobial properties
- 2022
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Ingår i: Biomaterials Advances. - : Elsevier. - 2772-9516 .- 2772-9508. ; 133
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Tidskriftsartikel (refereegranskat)abstract
- Additive manufacturing allows for the production of porous metallic implants for use in orthopaedics, providing excellent mechanical stability and osseointegration. However, the increased surface area of such porous implants also renders them susceptible to bacterial colonization. In this work, two trabecular porous Ti6Al4V alloys produced by electron beam melting were investigated for their osteocompatibility and antimicrobial effects, comparing samples with a silver-coated surface to uncoated samples. Dense grit-blasted Ti samples were used for comparison. The porous samples had pore sizes of 500-600 mu m and 5 to 10 mu m surface roughness, the silver-coated samples contained 7 at.% Ag, resulting in a cumulative Ag release of 3.5 ppm up to 28 days. Silver reduced the adhesion of Staphylococcus aureus to porous samples and inhibited 72 h biofilm formation by Staphylococcus epidermidis but not that of S. aureus. Primary human osteoblast adhesion, proliferation and differentiation were not impaired in the presence of silver, and expression of osteogenic genes as well as production of mineralized matrix were similar on silver-coated and uncoated samples. Our findings indicate that silver coating of porous titanium implants can achieve antimicrobial effects without compromising osteocompatibility, but higher silver contents may be needed to yield a sustained protection against fast-growing bacteria.
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| 3. |
- Apelgren, Peter, et al.
(författare)
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Biomaterial and biocompatibility evaluation of tunicate nanocellulose for tissue engineering.
- 2022
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Ingår i: Biomaterials advances. - : Elsevier BV. - 2772-9508. ; 137
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular matrix fibril components, such as collagen, are crucial for the structural properties of several tissues and organs. Tunicate-derived cellulose nanofibrils (TNC) combined with living cells could become the next gold standard for cartilage and soft-tissue repair, as TNC fibrils present similar dimensions to collagen, feasible industrial production, and chemically straightforward and cost-efficient extraction procedures. In this study, we characterized the physical properties of TNC derived from aquaculture production in Norwegian fjords and evaluated its biocompatibility regarding induction of an inflammatory response and foreign-body reactions in a Wistar rat model. Additionally, histologic and immunohistochemical analyses were performed for comparison with expanded polytetrafluoroethylene (ePTFE) as a control. The average length of the TNC as determined by atomic force microscopy was tunable from 3μm to 2.4μm via selection of a various number of passages through a microfluidizer, and rheologic analysis showed that the TNC hydrogels were highly shear-thinning and with a viscosity dependent on fibril length and concentration. As a bioink, TNC exhibited excellent rheological and printability properties, with constructs capable of being printed with high resolution and fidelity. We found that post-print cross-linking with alginate stabilized the construct shape and texture, which increased its ease of handling during surgery. Moreover, after 30days in vivo, the constructs showed a highly-preserved shape and fidelity of the grid holes, with these characteristics preserved after 90days and with no signs of necrosis, infection, acute inflammation, invasion of neutrophil granulocytes, or extensive fibrosis. Furthermore, we observed a moderate foreign-body reaction involving macrophages, lymphocytes, and giant cells in both the TNC constructs and PTFE controls, although TNC was considered a non-irritant biomaterial according to ISO 10993-6 as compared with ePTFE. These findings represent a milestone for future clinical application of TNC scaffolds for tissue repair. One sentence summary: In this study, the mechanical properties of tunicate nanocellulose are superior to nanocellulose extracted from other sources, and the biocompatibility is comparable to that of ePTFE.
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| 4. |
- Gomes-Ferreira, Pedro Henrique Silva, et al.
(författare)
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PTH 1-34-functionalized bioactive glass improves peri-implant bone repair in orchiectomized rats: Microscale and ultrastructural evaluation
- 2022
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Ingår i: Biomaterials Advances. - : Elsevier BV. - 2772-9508. ; 134
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this work was to investigate the use of Biogran® functionalized with parathyroid hormone (PTH) 1–34 by sonochemistry for the local delivery of this anabolic agent to the implant site. The effects of Biogran® and topical administration of PTH 1–34 on peri-implant bone regeneration were evaluated from the microscale to ultrastructural levels in healthy (SHAM) and orchiectomized (ORQ). While some animals only received a titanium implant in their tibial metaphyses (CLOT group), in others the peri-implant defect was first filled with Biogran® either without or with PTH 1–34 functionalization (BG and BGPTH groups, respectively) prior to implant installation. Osseointegration was characterized from a biomechanical perspective by measuring the removal torque with the counter-torque technique. Micro-CT was used to evaluate the percentage of bone volume, trabecular thickness, number and separation, and bone-implant contact (BIC). Dynamics of new bone formation were assessed by measuring fluorochrome area, daily mineral apposition rate, and neoformed bone area using confocal laser microscopy. RT-PCR was performed to evaluate ALP and osteocalcin expression. The interface between newly formed bone and Biogran® was examined using scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) at the micro-and nanoscale, respectively, while elemental analyses were completed in SEM with energy-dispersive X-ray spectroscopy (EDS). STEM imaging demonstrated the intimate attachment of bone to Biogran® (nanoscale level). Overall, the results suggest that the effectiveness of the topical administration of PTH 1–34 at the implant site seems enhanced in osteoporotic bone, promoting peri-implant bone regeneration to comparable levels in healthy conditions.
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