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Advancement in the Fabrication of Composites using Biocompatible Polymers for Biomedical Applications
Published in Atul Babbar, Ranvijay Kumar, Vikas Dhawan, Nishant Ranjan, Ankit Sharma, Additive Manufacturing of Polymers for Tissue Engineering, 2023
Nishant Ranjan, Sehra Farooq, Harnam Singh Farwaha
Poly N-Isopropylacrylamide (PNIPAAm) is a thermoresponsive polymer made by polymerizing N-isopropyl acrylamide via a free radical process (Alaghemandi & Spohr, 2012). The thermoresponsive characteristic of PNIPAAm allows it to be controlled to produce hydrogels, copolymerize, and graft synthetic polymers and biomolecules (Lanzalaco & Armelin, 2017). The procedure is carried out in combination with the newly added highly supervised polymerization technologies. PNIPAAm nanocomposites are a popular category of bioengineering elements that seem to be the focus of numerous thorough research topics in current biotechnology. Hydrogels based on PNIPAAm are being studied intensively for applications such as controlled administration of active compounds, regenerative medicine, tissue engineering, cell encapsulation, and self-healing materials (Xue et al., 2020). PCL and poly(ethylene glycol) (PEG) are likely the most favorable polymers for improving the biodegradability of PNIPAAm hydrogels. The recent advancements in 3D printing have led to the diverse design of PNIPAAm-incorporated medical tools and smart cell equipment that have an excellent stimuli-responsive character (Bo & Zia, 2012).
Bioresponsive Hydrogels for Controlled Drug Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Tamgue Serges William, Dipali Talele, Deepa H. Patel
Poly-N-isopropylacrylamide (pNIPAM) is a thermo-responsive polymer with inverse solubility and a reversible phase transition upon heating. It has a LCST value of approximately 32°C where below 32°C, polymer is hydro-philic and water soluble and above 32°C, it is hydrophobic and which then becomes a viscous gel strongly adhere to tissue. pNIPAM is soluble at room temperature but its phase separates at body temperature (37°C); thus it can be used as a linear polymer, a hydrogel, or a copolymer. pNIPAM polymer has been used in thermo-sensitive coatings or micelles for controlled release of the drug, drug targeting in solid tumors with local hyperthermia, in eye drop preparations and as a new embolic material in neurosurgery [26].
Multifunctional Hybrid Nanogels for Medicine
Published in Vladimir Torchilin, Handbook of Materials for Nanomedicine, 2020
Poly(N-isopropylacrylamide) (PNIPAm) is a thermoresponsive polymer with a lower critical solution temperature (LCST) of around 32°C which is suitable for medical applications. PNIPAm-based nanogels were reported in combination with Au nanoparticles (AuNPs) in a core–shell fashion (Au@PNIPAm nanogels) [44]. Au@PNIPAm nanogels were employed in cell imaging trespassing cellular barriers to enter the cytoplasm. 5-Fluorouracil (5-FU) served as a model anticancer drug to test the viability of HeLa cells upon exposure to 515 nm laser. Cell death increased significantly in the drug-loaded systems in comparison to non-loaded ones, which demonstrated the higher therapeutic efficacy of the combined chemo-photothermal treatments.
Facile synthesis of poly N-isopropylacrylamide/acrylamide-quantum dots hybrid hydrogels and their fluorescence temperature sensitive behaviors
Published in Soft Materials, 2020
Wenshan Gao, Siqi Gu, Jingyu Zhou, Yanan Li, Yajun Zhao, Jie Meng, Wenming Zhang
In recent years, inorganic/organic composite materials have attracted wide attention at home and abroad due to their versatilities. Semiconductor metallic nanocrystal quantum dots (QDs), as attractive materials, have received ever increasing attention because of their unique physical and optical properties[1–5] in the fields of nanomedicine[6], biological labeling[7], energy storage, drug delivery, catalysis[8], sensing, imaging[9], optoelectronics[10], light-emitting devices, solar cells and non-linear optical devices.[11] Poly (N-isopropylacrylamide) (PNIPAM) is a typical temperature sensitive polymer, which shows a coil-globule transition in aqueous solution at a lower critical solution temperature (LCST) of around 32°C and has been applied to several fields, for instance, extraction and purification of nucleic acids, controlled release, and controlled cell adhesion.[12–14]
Surface modification of PHBV nanofiber mats for rapid cell cultivation and harvesting
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Young-Gwang Ko, Young-Jin Kim, Won Ho Park, Donghwan Cho, Ho Yun Chung, Oh Hyeong Kwon
To solve these problems, we fabricated a thermo-responsive polymer-grafted nanofibrous surface to facilitate cell attachment, proliferation and accelerate harvesting speed compared to conventional polystyrene cell culture dishes (Figure 1). A number of reports have demonstrated that cell sheets harvested from a thermo-responsive polymer surface retain cell membrane-associated proteins [29–38]. Poly(N-isopropylacrylamide) (PNIPAM) is thermo-responsive polymer that has a lower critical solution temperature (LCST) at 32 °C and exhibits a phase separation behavior in water below 32 °C [32,38]. The PNIPAM-grafted surface can reversibly change its hydrophilic and hydrophobic surface properties in response to changes in temperature. Therefore, cells can be attached to the PNIPAM-grafted fibrous surface at a temperature above 32 °C and detached below 32 °C by hydration of the PNIPAM chain without dissociation of cell adhesion, membrane proteins, and enzymes. PNIPAM grafting on a cell culture substrate is an advanced approach for cell harvesting that does not result in the breaking of cell membrane proteins. However, reports on repeated stem cell cultivation on PNIPAM-grafted nanofibrous mats are rare compared to those on conventional tissue culture polystyrene dishes (TCPS). The results of this study will aid in the verification of the functionality of stem cells during repeated subculture on PNIPAM-grafted nanofiber mats. This study describes the preparation of thermo-responsive PNIPAM-grafted nonwoven PHBV nanofiber mats as an improved cell culture substrate for rapid cell harvesting and the characterization of proliferation, detachment, and functionality of attached ADSCs.