Dentin-Pulp Complex Regeneration
Vincenzo Guarino, Marco Antonio Alvarez-Pérez in Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Chitosan is a natural polymer derived from chitin. It is a biodegradable natural carbohydrate biopolymer that has shown to improve wound healing and bone formation. It is non-toxic and non-immunogenic. Depending on the type of polymer used, once the percentage of deacetylation of chitin gets to approximately 50%, chitin transforms to chitosan, which is soluble in aqueous acidic media. Chitosan is biocompatible and biodegradable and is currently used with other polymers in a variety of tissue engineering applications (Madihally and Matthew 1999; Suh and Matthew 2000; Seol et al. 2004). The uniqueness of this scaffold is its layered macroscale bio-mimetic structure with tunable mechanical characteristics that supports movement of the two cell types in all directions (Ravindran et al. 2010). Viability by using BMP-7 gene-activated chitosan/collagen scaffolds for human dental pulp stem cells has been previously demonstrated. One of the potential clinical applications of this chitosan scaffold may be the regeneration of the dentin—pulp complex. The elasticity of chitosan/ collagen scaffold supports the application of DPSC in pulp cavities to allow tissue generation. However, to progress to potential therapeutic application toward dentin regeneration, improved scaffold design in composition, as well as morphology, are essential.
Designing Biomaterials for Regenerative Medicine: State-of-the-Art and Future Perspectives
Naznin Sultana, Sanchita Bandyopadhyay-Ghosh, Chin Fhong Soon in Tissue Engineering Strategies for Organ Regeneration, 2020
The synthetic biodegradable polymers are major groups of polymers that are popular in tissue engineering. These biodegradable and noncytotoxic materials can support cell attachment, proliferation and differentiation to reconstruct tissue defect (Guelcher 2008). A major difference between natural biopolymers and synthetic polymers is in their structures. Most synthetic polymers have much simpler than natural polymer structures. The degradation rate of these groups of materials are adjustable by changing the mixing ratio, molecular weight of components and other parameters to match with the regeneration rate of the tissue. Polyanhydrides, polyesters, polyphosphazenes, poly (glycerol sebacate) and polyurethanes are classified in this group of materials. This group can be manipulated to the desirable characteristics. Since polyanhydrides possess high hydrophobicity and favorable degradation pattern (degradation from the surface to the inside), they are appropriate for drug-delivery applications (Jain et al. 2008).
A ‘Biomaterial Cookbook’: Biochemically Patterned Substrate to Promote and Control Vascularisation in Vitro and in Vivo
Harishkumar Madhyastha, Durgesh Nandini Chauhan in Nanopharmaceuticals in Regenerative Medicine, 2022
Synthetic biomaterials include a wide range of polymers, ranging from biopolymer mimetics to fully synthetic products, that encompass a broad range of chemical, physical, and functional properties (Frassica & Grunlan, 2020). Achieving chemical, mechanical, and biomolecular mimicry of the ECM using synthetic polymers can be accomplished, thus overcoming many limitations associated to natural or protein-based polymers, although concerns remain regarding the long-term safety/biocompatibility and degradation/bioresorbability (Alaribe, Manoto, & Motaung, 2016; Bao, Le, Minh, Nguyen, & Minh, 2013). Synthetic polymer scaffolds typically include various polyacrylamides (e.g., PAA, PNIPAm), poly(2-hydroxyethyl methacrylate) (pHEMA), polyvinyl alcohol and polyvinyl acetate (PVA and PVAc), and polyethylene glycol (Table 14.1) (Cross & Claesson-Welsh, 2001).
Microencapsulated soil conditioner with a water-soluble core: improving soil nutrition of crop root
Published in Journal of Microencapsulation, 2021
Wang Zuo, Wang Jincheng, Song Shiqiang, Rao Pinhua, Wang Runkai, Liu Shihui
The W/O/W system had successfully entrapped water-soluble substance, while there was the most conundrum challenge to keep the emulsion stable (Estevez et al.2019). The system was potential to be unstable because of flocculation coalescence and aggregation of liquid droplets, also was due to the access forming between internal and external phases (Chen et al.2018). Compared with the strategies which stabilised the W/O/W emulsions with developing hydrophilic emulsifiers, it was a speeded and effective method to maintain an anticipated structure with instantaneously solidifying by the outer solution. The natural polymer could be widely used in agricultural sector because of their biocompatibility and environmental safety (Mishra et al.2018). In addition, as a type of natural material, the sodium alginate can be used as water holding microspheres and possesses potential to retain water solution in root environment (Belscak-Cvitanovic et al.2015, Thombare et al. 2018).
Chitosan-biotin topical film: preparation and evaluation of burn wound healing activity
Published in Pharmaceutical Development and Technology, 2022
Faisal Al-Akayleh, Nisrein Jaber, Mayyas Al-Remawi, Ghazi Al Odwan, Nidal Qinna
Chitin is the second most abundant natural biopolymer after cellulose. Partial deacetylation of chitin results in the formation of chitosan (CS). The sugar backbone of CS is consisting of β-1,4 linked glucosamine with a high degree of N-acetylation. Besides its versatile applications, CS has excellent biological properties including wound healing due to its biocompatibility, biodegradability, non-toxicity, low cost, and antimicrobial activity (Jaber et al. 2022; Obaidat et al. 2010; Bakshi et al. 2020). Moreover, CS and its wide range of derivatives have attracted numerous attention because of its efficient activity in all stages of the wound healing process, stimulation of immune response, and easy processability into different pharmaceutical dosage forms (Stephen-Haynes et al. 2014; Moeini et al. 2020).
Localized, on-demand, sustained drug delivery from biopolymer-based materials
Published in Expert Opinion on Drug Delivery, 2022
Junqi Wu, Sawnaz Shaidani, Sophia K. Theodossiou, Emily J. Hartzell, David L. Kaplan
Natural biopolymer systems offer particularly tunable features for degradation compared to synthetic polymer systems. Biopolymer degradation typically utilizes enzymatic mechanisms, as opposed to the chemical hydrolysis in most polyester synthetic polymers. With enzymatic degradation, the mechanism is mainly based on surface erosion, whereas chemical hydrolysis leads to bulk degradation. In terms of drug release and structural integrity, surface degradation is a more controlled process that can be engineered: since the implant is degraded layer by layer, the integrity of the implant is maintained without abrupt failure. Conversely, synthetic polymer-based implants degrade through chemical hydrolysis, driven by bulk degradation, where the implants are likely to collapse, leading to burst release and a more inflammatory response in vivo.