China
Africa
Explore chapters and articles related to this topic
Two-Dimensional Nanomaterials for Drug Delivery in Regenerative Medicine
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Zahra Mohammadpour, Seyed Morteza Naghib
Transition metal dichalcogenides (TMDs) are another class of 2Dnanomaterials, which have widely been used in biomedicine. Biocompatibility, high photothermal conversion efficiency, and enzyme-mimic property are among several merits that give TMDs unprecedented capabilities in biomedicine. Liu et al. proposed an enzyme-responsive nanosystem to fight drug-resistant bacteria (Liu et al. 2019b). In their design, mesoporous ruthenium nanoparticles were loaded with ascorbic acid (AA) and coated with HA. In response to an enzyme called Hyal from the bacteria, the HA coating was degraded and AA was released. H2O2, as a pro-drug of AA, was converted to toxic hydroxyl radicals by the peroxidase mimic activity of MoS2 nanosheets. The chemotherapeutic effect was synergised with the photothermal property of ruthenium nanoparticles. In vivo results of wound healing proved the efficiency of the chemo/phototherapeutic system within ten days of treatment. In an attempt to develop biomaterial scaffolds, Jaiswal et al. fabricated self-assembled nanocomposite hydrogels driven by the atomic vacancies in the structure of MoS2 nanoassemblies (Jaiswal et al. 2017). The chemically cross-linked hydrogels consisted of defect-rich MoS2 and polymeric binders. The atomic vacancies in the MoS2 structure acted as an active site for the chemisorption of thiolated PEG. The gelation proceeded without UV exposure or the use of chemical initiators. Therefore, it provided a safe and non-toxic strategy to encapsulate cells in the hydrogels. More than 85% of cell viability was observed after encapsulation. The authors proposed that the vacancy-driven gelation process is a facile route for the preparation of bioactive hydrogels for use in regenerative medicine and therapeutic delivery. A summary of the applications of 2D nanomaterials in regenerative medicine is given in Table 2.1.
Injectable Scaffolds for Bone Tissue Repair and Augmentation
Published in Naznin Sultana, Sanchita Bandyopadhyay-Ghosh, Chin Fhong Soon, Tissue Engineering Strategies for Organ Regeneration, 2020
Subrata Bandhu Ghosh, Kapender Phogat, Sanchita Bandyopadhyay-Ghosh
CNC-reinforced nanocomposite based on injectable polysaccharide hydrogels were studied for in vitro cytotoxicity by using a cell viability MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay with NIH 3T3 fibroblast cells. Minimal decreases in relative cell viability was observed after 1 day of cell exposure. It was also reported that none of the hydrogels had significant cytotoxicity, indicating promising potential of the hydrogels for bone tissue engineering (Yang et al. 2013, De France et al. 2017). Domingues et al. reported development of an injectable bionaocomposite hydrogels composed of adipic acid dihydrazide-modified hyaluronic acid (ADH-HA) reinforced with aldehyde-modified CNCs (a-CNCs). The surface of nanocomposites was examined after 1, 3 and 7 days of cell culture to investigate the ability of developed hydrogels to support the cell adhesion (Domingues et al. 2015). HA-CNC based nanocomposite hydrogels demonstrated cell supportive properties, possibly because of enhanced structural integrity and possible interactions of micro-environmental cues with CNC’s sulphate groups (De France et al. 2017, Domingues et al. 2015). Besides, the hydrogels exhibited pronounced proliferative activity. The ability of developed nanocomposites to encapsulate cells and to control cellular behavior were investigated through studies on DNA content, metabolic activity and viability of encapsulated human adipose tissue derived mesenchymal stem cells (hASCs), following their culture at 1, 3 and 7 days. Mitochondrial activity of the cells within the nanocomposites was evaluated by Alamar Blue assay (Domingues et al. 2015). In another study, in vitro degradation behaviour of an injectable bone regeneration composites (IBRC) which comprised of nano-hydroxyapatite/collagen particles in alginate hydrogel carrier was investigated . In vitro results showed that immersion medium (SBF) had influence on degradation of alginate molecules (Petinakis et al. 2010).
Polymer-based thermoresponsive hydrogels for controlled drug delivery
Published in Expert Opinion on Drug Delivery, 2022
Nanocomposite hydrogels include also those derived from the physical or chemical interaction between the hydrogel and the polymeric nanoparticles; their presence can control the swelling/deswelling behavior and the mechanical property of the final gel. PNIPAM hydrogels containing cross-linked poly(acrylamide) nanoparticles showed larger equilibrium water uptake and faster swelling/deswelling rate compared with conventional hydrogels. Moreover, the volume phase transition temperature is dependent on the nanoparticle content: the higher the nanoparticles amount, the higher the volume phase transition temperature [134]. Polymeric nanoparticles can be used not only to improve the mechanical property of the gel, but also as a thermo-responsible system for the drug delivery compensating a low or absence of thermo-sensitivity of the hydrogel itself. For example, a composite hydrogel characterized by a poly(ethylene glycol) diacrylate (PEGDA) matrix containing thermo-responsive poly(N-isopropylacrylamide-co-acrylamide) (PNIPAM-Aam) nanoparticles can work in this direction [135]. The hydrogel is able to photopolymerize in situ by using an ultraviolet (UV) light and release drug and/or protein only by changing the temperature locally above the LCST of the nanoparticles (39–40°C). Protein release study showed quicker release of the model protein (bovine serum albumin) from the hydrogel at 40°C compared with that at 23°C, because of the collapse of PNIPAM at temperature higher than LCST and consequent compression, which leads to the release of protein.
Application of Platelet Rich Fibrin in Tissue Engineering: Focus on Bone Regeneration
Published in Platelets, 2021
Ahmad Reza Farmani, Mohammad Hossein Nekoofar, Somayeh Ebrahimi Barough, Mahmoud Azami, Nima Rezaei, Sohrab Najafipour, Jafar Ai
Moreover, drugs or growth factors can also be incorporated into their structure, which can accelerate the bone formation process [14]. Nanocomposite hydrogels containing nano-fibers or ceramic nanoparticles have been created a new generation of these scaffolds [15–18]. Considering the importance of the interaction of scaffolds with the immune system; the concept of osteoimmunomodulation (OIM) has been developed [19,20]. Moreover, human origin biomaterials are used for bone tissue engineering, based on the transplant source can be referred to as frozen bone, allograft freeze-dried bone (FDBA), and demineralized allograft freeze-dried bone (DFDBA), which successfully has been used for healing bone defects. Biomaterials derived from blood also have great importance, which is related to the ease of harvesting and the presence of the growth factors in them [21]. In an interesting study, it has been shown that even adding blood itself, or along with other biomaterials has significantly improved angiogenesis in the lesion site [22]. Nowadays, several types of blood-derived biomaterials are used in clinics.
Halloysites modified polyethylene glycol diacrylate/thiolated chitosan double network hydrogel combined with BMP-2 for rat skull regeneration
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Qi-Bin Sun, Chang-Peng Xu, Wen-Qiang Li, Qin-Jun Meng, Hua-Zheng Qu
The fabrication of nanocomposite hydrogels is a desirable method that can enhance the mechanical behaviour of hydrogel [26,27]. In this work, PEGDA/TCS/T-HNTs hydrogel was designed and further cross-linked by two-step procedure of UV photopolymerization and TPP physical crosslinking. The synthesis schematic diagram was shown in Figure 2(A). It's worth noting that mechanism of TPP as ionic cross-linker based on negatively charged groups reaction with positively charged amino groups of chitosan [28]. TPP has the advantages of stable performance, simple process control and safety and have been s become a widely used technology in the preparation crosslinking chitosan hydrogel. Figure 2(B(a–c)) shows a compression graph of the resulting hydrogels, which indicates good compression resistance for the hydrogel.