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Recent Developments in Bioresponsive Drug Delivery Systems
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Drashti Pathak, Deepa H. Patel
Use of polymers in biomedical materials applications—e.g., as pros-theses, medical devices, contact lenses, dental materials, and pharmaceutical excipients—is long-established, but polymer-based medicines have only recently entered routine clinical practice [30–33]. Much innovative polymer-based therapeutics once dismissed as interesting but impractical scientific curiosities have now shown that they can satisfy the stringent requirements of industrial development and regulatory authority approval.
Nonclinical Safety Evaluation of Medical Devices
Published in Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard, Toxicologic Pathology, 2018
Kathleen A. Funk, Victoria A. Hampshire, JoAnn C. L. Schuh
Toxicologic pathologists working with biomaterials and devices for the first time will need to learn about the biochemical characteristics of biomaterials, gross appearance of medical devices, and compatibility of materials with standard histologic processing for paraffin-embedded blocks or deciding whether the material will require a specialized procedure for sample collection and histologic preparation and staining. Only then can the microscopic appearance of biomaterials and finished devices and expected host responses be fully interpreted. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM), immunohistochemistry, ex vivo tissue extractions, in vivo imaging, and semi-quantitative and quantitative evaluations are tools familiar to toxicologic pathologists that will be useful to determine biocompatibility and terminal resolution of reactions to biomaterials. Familiarity with animal models of human disease, particularly models in larger species, and a thorough grasp of comparative pathology of human diseases is also of great advantage to working in medical device development. Monitoring relevant literature for medical device sciences also extends beyond veterinary and toxicology journals (Toxicologic Pathology, Veterinary Pathology, Comparative Medicine, International Journal of Toxicology, and Toxicologic Sciences) into bioengineering and material-based journals (Biomaterials, Journal of Biomedical Materials Research, Materials, Acta Biomaterialia, Journal of Bioactive and Compatible Polymers: Biomedical Applications, Advanced Materials, Polymers for Advanced Technologies, and Nature Materials). Relevant textbook references also cross multiple disciplines (Badylak 2015; Boutrand 2012; Gad and Gad-McDonald 2015; Goud 2016; Haschek et al. 2013; Ratner et al. 2013; Von Recum 1998; Wnek and Bowlin 2008).
Stereolithography 3D printing technology in pharmaceuticals: a review
Published in Drug Development and Industrial Pharmacy, 2021
Subhash Deshmane, Prakash Kendre, Hitendra Mahajan, Shirish Jain
The choice of photopolymer is of utmost importance in SLA [94,95]. The lack of approval of photosensitive materials by the regulatory authority (the FDA) limits the use of SLA significantly, even though photosensitive materials are used in tissue engineering. During the last decade, a number of photocrosslinkable polymers have been developed. Poly(ethylene glycol) diacrylate (PEGDA) [73,96], poly(2-hydroxyethyl methacrylate) (pHEMA) [97], poly(ethylene glycol) dimethacrylate (PEGDMA) [98,99] and poly(propylene fumarate)/diethyl fumarate (PPF/DEF) [100,101] are examples of photocrosslinkable polymers. Biomedical materials have applications in surgical tools, hearing aids, knee joint appliances and dental appliances [102]. The multiple resins for one build showed patterning with PEG-DMA and PEG-DA with fluorescently labeled dextran, fluorescently labeled bioactive PEG or bioactive PEG in different regions of the scaffold [103]. Complex 3D scaffolds can be fabricated using photocrosslinkable poly(propylene fumarate) (PPF) [104,105], which requires reactive diluents containing significant amounts of non-degradable components. N-vinyl-2-pyrrolidone and diethyl fumarate are used as diluents to reduce the viscosity of the resin during processing [106]. Reconstruction of cranial defects in rabbits is possible because of the ability to produce controlled microstructures [89]. Trimethylene carbonate, polycaprolactone and poly(D,L-lactide) are examples of materials used commonly in tissue engineering [107,108].
Graphene oxide nanoparticles induce hepatic dysfunction through the regulation of innate immune signaling in zebrafish (Danio rerio)
Published in Nanotoxicology, 2020
Guanghua Xiong, Yunyun Deng, Xinjun Liao, Jun’e Zhang, Bo Cheng, Zigang Cao, Huiqiang Lu
Previous studies have showed that environmental toxicants could induce the mRNA expression of innate immune genes (Tu et al. 2013; Zhu et al. 2015). On activation through TLRs, immune cells initiate a signaling cascade that includes adaptor proteins such as MyD88, which leads to nuclear translocation of transcription factors such as NF-κB p65 as well as the production of inflammatory cytokines (Fernandez-Figueroa et al. 2016). In the present study, 1 mg/L GO exposure significantly activated TLR immune signaling and increased the expressions of NF-κB p65, JAK2, STAT3, and Bcl-2 at the protein levels. Furthermore, we evaluated whether the liver malformation phenotypes induced by GO was mediated by ROS and PPAR-α mediated MAPK signaling pathway. Our results suggested that inhibiting of ROS and MAPK signaling could obviously reverse the GO-induced liver injury in zebrafish, while activation of PPAR-α obviously aggravated the liver damage in adult zebrafish. These results further demonstrated that GO induced liver damage was mainly through the ROS and PPAR-α mediated MAPK signaling in zebrafish. In conclusion, the present study brings some new insights into the molecular mechanisms of GO nanotoxicity including possible effects on liver development, immunotoxicity, oxidative stress, and apoptosis in the larval and adult zebrafish. These informations will be valuable for the risk management and provide new guidance for reduction of the hazardous effects of nano-scale biomedical materials.
Improved intestinal absorption of paclitaxel by mixed micelles self-assembled from vitamin E succinate-based amphiphilic polymers and their transcellular transport mechanism and intracellular trafficking routes
Published in Drug Delivery, 2018
Xiaoyou Qu, Yang Zou, Chuyu He, Yuanhang Zhou, Yao Jin, Yunqiang Deng, Ziqi Wang, Xinru Li, Yanxia Zhou, Yan Liu
Biocompatibility is a great concern for biomedical materials. In order to address the cytocompatibility of micelle-forming materials with Caco-2 cells, their cytotoxicity toward Caco-2 cells by MTT assay was therefore assessed. As shown in Figure 3(E) a relative cell viability ranging from (102.3 ± 5.0)% to (112.5 ± 2.3)% was observed for blank PV-PMs up to the concentration of 12 mg/mL PEOz-VES, suggesting that PEOz-VES exhibited excellent biocompatibility with cells and was a favorable micelle-forming biomaterial for drug delivery. In contrast, the cell viability for blank TPGS1000-PMs-treated group was higher than 82% at concentrations ranging from 0.5 to 12 mg/mL TPGS1000, indicating that TPGS1000 also had better biocompatibility with cells, but it was a little inferior to PEOz-VES. Similarly, the blank Mix-PMs exhibited almost no toxicity against Caco-2 cells up to a concentration of 12 mg/mL polymer. In conclusion, PEOz-VES exhibited higher safety compared with TPGS1000, and the influence of blank PV-PMs and Mix-PMs on cell viability could be ignored in the subsequent studies.