An injectable and self-healing hydrogel with covalent cross-linking in vivo for cranial bone repair

2017 ◽  
Vol 5 (20) ◽  
pp. 3739-3748 ◽  
Author(s):  
Shaoyu Lü ◽  
Xiao Bai ◽  
Haidi Liu ◽  
Piao Ning ◽  
Zengqiang Wang ◽  
...  
Keyword(s):  
Click Chemistry ◽  
Bone Repair ◽  
Cranial Bone ◽  
Cross Linking ◽  
Self Healing

DA click chemistry and dynamic acylhydrazone bond cross-linking are employed to obtain injectable and self-healing hydrogels for cranial bone repair.

scholarly journals Adhesive liposomes loaded onto an injectable, self-healing and antibacterial hydrogel for promoting bone reconstruction

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Lili Liu ◽  
Yi Xiang ◽  
Zhen Wang ◽  
Xiaonan Yang ◽  
Xiaohua Yu ◽  
...  
Keyword(s):  
Osteogenic Differentiation ◽  
Osteoporotic Fractures ◽  
Cross Linking ◽  
Self Healing ◽  
Bone Reconstruction ◽  
Peg Hydrogels ◽  
Marrow Cavity ◽  
Local Bone

AbstractLoading hydrogels with bioactive agents is an important method for expanding the functional application of hydrogels. However, how to improve the local administration and slow release of drugs from a hydrogel is a challenge when using hydrogels loaded with drugs. In this paper, we first developed adhesive liposomes (A-LIP) loaded with BMP-2. Then, we incorporated the A-LIP into PEG hydrogels based on the coordinated cross-linking principle of SH-PEG and Ag+, fabricating an injectable, antibacterial and self-healing multifunctional drug delivery system. The adhesive lipo-hydrogel (A-LIP-PEG) fabricated by mixing PEG hydrogels and adhesive liposomes can be locally injected into an osteoporotic fracture and bone marrow cavity, where A-LIP-PEG can release adhesive liposomes that adhere to the bone injury area and promote bone reconstruction. Based on the principle of electrostatic attraction, tissue nonspecific A-LIP were fabricated by grafting octadecylamine onto liposomes. Because of the coordination and cross-linking of thiolated polyethylene (SH-PEG) and Ag+, the A-LIP-PEG showed excellent injectability and self-healing properties; further, because of the presence of Ag+, the A-LIP-PEG showed effective inhibition of S. aureus and Escherichia coli. The liposomes released by the A-LIP-PEG were able to adhere to tissue. In vitro studies showed that A-LIP-PEG significantly promoted osteogenic differentiation and had no significant effect on cell proliferation. Compared with common lipo-hydrogel (LIP-PEG), the A-LIP-PEG had better tissue adhesion in vivo, which led to better osteogenic differentiation and faster local bone remodeling of osteoporotic fractures in rats. This research developed a novel hydrogel system with adhesive liposomes to expand the application of hydrogels.

scholarly journals BMP-2 and VEGF-A modRNAs in collagen scaffold synergistically drive bone repair through osteogenic and angiogenic pathways

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yingnan Geng ◽  
Huichuan Duan ◽  
Liang Xu ◽  
Nevin Witman ◽  
Bingqian Yan ◽  
...  
Keyword(s):  
Bone Repair ◽  
Expression Profiles ◽  
Collagen Scaffold ◽  
Self Healing ◽  
Chemically Modified ◽  
Bone Injury ◽  
Rate Of Recovery ◽  
Regenerative Therapies ◽  
Non Surgical Treatment

AbstractBone has a remarkable potential for self-healing and repair, yet several injury types are non-healing even after surgical or non-surgical treatment. Regenerative therapies that induce bone repair or improve the rate of recovery are being intensely investigated. Here, we probed the potential of bone marrow stem cells (BMSCs) engineered with chemically modified mRNAs (modRNA) encoding the hBMP-2 and VEGF-A gene to therapeutically heal bone. Induction of osteogenesis from modRNA-treated BMSCs was confirmed by expression profiles of osteogenic related markers and the presence of mineralization deposits. To test for therapeutic efficacy, a collagen scaffold inoculated with modRNA-treated BMSCs was explored in an in vivo skull defect model. We show that hBMP-2 and VEGF-A modRNAs synergistically drive osteogenic and angiogenic programs resulting in superior healing properties. This study exploits chemically modified mRNAs, together with biomaterials, as a potential approach for the clinical treatment of bone injury and defects.

Click Chemistry Expedited Radiosynthesis: Sulfur [18F]fluoride Exchange of Aryl Fluorosulfates

2019 ◽  
Author(s):  
Qinheng Zheng ◽  
Hongtao Xu ◽  
Hua Wang ◽  
Wen-Ge Han Du ◽  
Nan Wang ◽  
...  
Keyword(s):  
Click Chemistry ◽  
High Performance ◽  
Isotopic Exchange ◽  
Tumor Imaging ◽  
Radiochemical Yield ◽  
Exchange Method ◽  
Molar Activity ◽  
Positron Emission ◽  
Sulfur Fluoride

The lack of simple, efficient [<sup>18</sup>F]fluorination processes and new target-specific organofluorine probes remains the major challenge of fluorine-18-based positron emission tomography (PET). We report here a fast isotopic exchange method for the radiosynthesis of aryl [<sup>18</sup>F]fluorosulfate based PET agents enabled by the emerging sulfur fluoride exchange (SuFEx) click chemistry. The method has been applied to the fully-automated <sup>18</sup>F-radiolabeling of twenty-five structurally diverse aryl fluorosulfates with excellent radiochemical yield (83–100%) and high molar activity (up to 281 GBq µmol<sup>–1</sup>) at room temperature in 30 seconds. The purification of radiotracers requires no time-consuming high-performance liquid chromatography (HPLC), but rather a simple cartridge filtration. The utility of aryl [<sup>18</sup>F]fluorosulfate is demonstrated by the <i>in vivo</i> tumor imaging by targeting poly(ADP-ribose) polymerase 1 (PARP1).

Regeneration of Bone Defects Using Bioactive Glass Combined with Adipose-derived Mesenchymal Stem Cells. An experimental in vivo study

2019 ◽  
Vol 70 (6) ◽  
pp. 1983-1987
Author(s):  
Cristian Trambitas ◽  
Anca Maria Pop ◽  
Alina Dia Trambitas Miron ◽  
Dorin Constantin Dorobantu ◽  
Flaviu Tabaran ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Bioactive Glass ◽  
Bone Repair ◽  
Bone Defects ◽  
Calvarial Bone ◽  
Specific Protocol ◽  
Repair Mechanisms ◽  
Male Wistar Rats

Large bone defects are a medical concern as these are often unable to heal spontaneously, based on the host bone repair mechanisms. In their treatment, bone tissue engineering techniques represent a promising approach by providing a guide for osseous regeneration. As bioactive glasses proved to have osteoconductive and osteoinductive properties, the aim of our study was to evaluate by histologic examination, the differences in the healing of critical-sized calvarial bone defects filled with bioactive glass combined with adipose-derived mesenchymal stem cells, compared to negative controls. We used 16 male Wistar rats subjected to a specific protocol based on which 2 calvarial bone defects were created in each animal, one was filled with Bon Alive S53P4 bioactive glass and adipose-derived stem cells and the other one was considered control. At intervals of one week during the following month, the animals were euthanized and the specimens from bone defects were histologically examined and compared. The results showed that this biomaterial was biocompatible and the first signs of osseous healing appeared in the third week. Bone Alive S53P4 bioactive glass could be an excellent bone substitute, reducing the need of bone grafts.

scholarly journals Biomimetic reduced graphene oxide coated collagen scaffold for in situ bone regeneration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sajad Bahrami ◽  
Nafiseh Baheiraei ◽  
Mostafa Shahrezaee
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Cranial Bone ◽  
Drying Methods ◽  
Porous Scaffolds ◽  
Alizarin Red ◽  
Reduced Graphene ◽  
Coated Collagen

AbstractA variety of bone-related diseases and injures and limitations of traditional regeneration methods require new tissue substitutes. Tissue engineering and regeneration combined with nanomedicine can provide different natural or synthetic and combined scaffolds with bone mimicking properties for implantation in the injured area. In this study, we synthesized collagen (Col) and reduced graphene oxide coated collagen (Col-rGO) scaffolds, and we evaluated their in vitro and in vivo effects on bone tissue repair. Col and Col-rGO scaffolds were synthesized by chemical crosslinking and freeze-drying methods. The surface topography, and the mechanical and chemical properties of scaffolds were characterized, showing three-dimensional (3D) porous scaffolds and successful coating of rGO on Col. The rGO coating enhanced the mechanical strength of Col-rGO scaffolds to a greater extent than Col scaffolds by 2.8 times. Furthermore, Col-rGO scaffolds confirmed that graphene addition induced no cytotoxic effects and enhanced the viability and proliferation of human bone marrow-derived mesenchymal stem cells (hBMSCs) with 3D adherence and expansion. Finally, scaffold implantation into rabbit cranial bone defects for 12 weeks showed increased bone formation, confirmed by Hematoxylin–Eosin (H&E) and alizarin red staining. Overall, the study showed that rGO coating improves Col scaffold properties and could be a promising implant for bone injuries.

scholarly journals Fabrication of 3D-Printed Interpenetrating Hydrogel Scaffolds for Promoting Chondrogenic Differentiation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2146
Author(s):  
Jian Guan ◽  
Fu-zhen Yuan ◽  
Zi-mu Mao ◽  
Hai-lin Zhu ◽  
Lin Lin ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Elastic Modulus ◽  
Chondrogenic Differentiation ◽  
Marker Genes ◽  
Self Healing ◽  
Polyethylene Glycol Diacrylate ◽  
3D Microenvironment ◽  
3D Printed

The limited self-healing ability of cartilage necessitates the application of alternative tissue engineering strategies for repairing the damaged tissue and restoring its normal function. Compared to conventional tissue engineering strategies, three-dimensional (3D) printing offers a greater potential for developing tissue-engineered scaffolds. Herein, we prepared a novel photocrosslinked printable cartilage ink comprising of polyethylene glycol diacrylate (PEGDA), gelatin methacryloyl (GelMA), and chondroitin sulfate methacrylate (CSMA). The PEGDA-GelMA-CSMA scaffolds possessed favorable compressive elastic modulus and degradation rate. In vitro experiments showed good adhesion, proliferation, and F-actin and chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) on the scaffolds. When the CSMA concentration was increased, the compressive elastic modulus, GAG production, and expression of F-actin and cartilage-specific genes (COL2, ACAN, SOX9, PRG4) were significantly improved while the osteogenic marker genes of COL1 and ALP were decreased. The findings of the study indicate that the 3D-printed PEGDA-GelMA-CSMA scaffolds possessed not only adequate mechanical strength but also maintained a suitable 3D microenvironment for differentiation, proliferation, and extracellular matrix production of BMSCs, which suggested this customizable 3D-printed PEGDA-GelMA-CSMA scaffold may have great potential for cartilage repair and regeneration in vivo.

scholarly journals Bone defect reconstruction via endochondral ossification: A developmental engineering strategy

2021 ◽  
Vol 12 ◽  
pp. 204173142110042
Author(s):  
Rao Fu ◽  
Chuanqi Liu ◽  
Yuxin Yan ◽  
Qingfeng Li ◽  
Ru-Lin Huang
Keyword(s):  
Bone Regeneration ◽  
Bone Defect ◽  
Bone Repair ◽  
Endochondral Ossification ◽  
Current Knowledge ◽  
Endochondral Bone ◽  
Defect Reconstruction ◽  
Hypoxic Conditions ◽  
Bone Defect Reconstruction

Traditional bone tissue engineering (BTE) strategies induce direct bone-like matrix formation by mimicking the embryological process of intramembranous ossification. However, the clinical translation of these clinical strategies for bone repair is hampered by limited vascularization and poor bone regeneration after implantation in vivo. An alternative strategy for overcoming these drawbacks is engineering cartilaginous constructs by recapitulating the embryonic processes of endochondral ossification (ECO); these constructs have shown a unique ability to survive under hypoxic conditions as well as induce neovascularization and ossification. Such developmentally engineered constructs can act as transient biomimetic templates to facilitate bone regeneration in critical-sized defects. This review introduces the concept and mechanism of developmental BTE, explores the routes of endochondral bone graft engineering, highlights the current state of the art in large bone defect reconstruction via ECO-based strategies, and offers perspectives on the challenges and future directions of translating current knowledge from the bench to the bedside.

scholarly journals Chemically-Boosted Corneal Cross-Linking for the Treatment of Keratoconus through a Riboflavin 0.25% Optimized Solution with High Superoxide Anion Release

2021 ◽  
Vol 10 (6) ◽  
pp. 1324
Author(s):  
Cosimo Mazzotta ◽  
Marco Ferrise ◽  
Guido Gabriele ◽  
Paolo Gennaro ◽  
Alessandro Meduri
Keyword(s):  
Superoxide Anion ◽  
Hydroxypropyl Methylcellulose ◽  
Anterior Segment ◽  
Preclinical Study ◽  
Cross Linking ◽  
Specular Microscopy ◽  
The Novel ◽  
Power Setting ◽  
Contralateral Eye

The purpose of this study was to evaluate the effectiveness and safety of a novel buffered riboflavin solution approved for corneal cross-linking (CXL) in progressive keratoconus and secondary corneal ectasia. Following the in vivo preclinical study performed on New Zealand rabbits comparing the novel 0.25% riboflavin solution (Safecross®) containing 1% hydroxypropyl methylcellulose (HPMC) with a 0.25% riboflavin solution containing 0.10% EDTA, accelerated epithelium-off CXL was performed on 10 patients (10 eyes treated, with the contralateral eye used as control) through UV-A at a power setting of 9 mW/cm2 with a total dose of 5.4 J/cm2. Re-epithelialization was evaluated in the postoperative 7 days by fluorescein dye test at biomicroscopy; endothelial cell count and morphology (ECD) were analyzed by specular microscopy at the 1st and 6th month of follow-up and demarcation line depth (DLD) measured by anterior segment optical coherence tomography (AS-OCT) one month after the treatment. We observed complete re-epithelization in all eyes between 72 and 96 h after surgery (88 h on average). ECD and morphology remained unchanged in all eyes. DLD was detected at a mean depth of 362 ± 50 µm, 20% over solutions with equivalent dosage. SafeCross® riboflavin solution chemically-boosted corneal cross-linking seems to optimize CXL oxidative reaction by higher superoxide anion release, improving DLD by a factor of 20%, without adverse events for corneal endothelium.

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