Biocompatibility Biodegradability

One can conclude that PVA hydrogels represent an efficient encapsulation vehicle for the studied porphyrins, both water soluble and non-water soluble. Their biocompatible, biodegradable, non-toxic, and non-carcinogenic nature makes them especially effective for pharmaceutical applications, but also for environmental uses, such as advanced wastewater... 

However, PVA is also extensively used in other different forms, such as gel matrices, micro and nano spheres, aerosols, aqueous solution, films, powder etc. Although some of the different types of PVA gels have been referred in chapter 3.3, it still remains much more to say. This clearly proves that PVA is an old, yet new polymer or, in other words, an old polymer with a promising future, due to its capacity to respond to all the actual society priorities clean technologies, non-toxicity, biocompatibility, biodegradability, intelligent materials. 

Chitosan, the most abundant marine mucopolysaccharide, is derived from chitin by alkaline deacetylation, and possesses versatile biological properties such as biocompatibility, biodegradability, and a non-toxic nature. Due to these characteristics, considerable attention has been given to its industrial applications in the food, pharmaceutical, agricultural, and environmental industries. Currently, chitosan can be considered as a potential marine nutraceutical because its remarkable biological activities have been investigated and reported, in order to exploit its nutraceutical... 

Biocompatibility Biodegradability Mucoadhesion Interaction with cell surface... 

Dextran is a physiologically harmless biopolymer because of its biocompatible, biodegradable, non-immunogenic and non-antigenic properties [54, 55]. It can be depolymerised by different a-l-glycosidases (dextranases) occurring in liver, spleen, kidney and lower part of the gastrointestinal tract. 

Work in this field has concentrated on the use of poly(lactide-co-glycolide) microparticles, which have the advantages of being biocompatible, biodegradable and well tolerated in humans. Promising results have also been obtained with the use of biodegradable starch microspheres in conjunction with the absorption enhancer lysophosphatidylcholine. 

Nonetheless, a (partial) switch to renewables is desirable for other reasons, such as biocompatibility, biodegradability and lower toxicity, i.e. renewable raw materials leave a smaller environmental footprint [3]. That the chemical industry has been slow to make the transition, in the three decades following the Report of the Club of Rome, is a consequence of the fact that oil and natural gas are excellent basic feedstocks and highly atom efficient, low waste, catalytic procedures are available for their conversion into commodity chemicals. The same cannot be said for the fine chemicals industry where processes are, generally speaking, much less efficient in many respects and there is considerable room for improvement. 

Another key topic - renewable resources - is addressed in Chapter 8. The utilization of fossil resources as sources of energy and chemical feedstocks is clearly unsustainable and needs to be replaced by the use of renewable biomass. Such a switch is also desirable for other reasons such as biocompatibility, biodegradability and lower toxicity of the products compared to their oil-derived counterparts. Here again, the application of chemo- and biocatalysis will play an important underlying role. 

Niosomes In order to circumvent some of the limitations encountered with liposomes, such as their chemical instability, the cost and purity of the natural phospholipids, and oxidative degradation of the phospholipids, niosomes have been developed. Niosomes are nonionic surfactant vesicles which exhibit the same bilay-ered structures as liposomes. Their advantages over liposomes include improved chemical stability and low production costs. Moreover, niosomes are biocompatible, biodegradable, and nonimmunogenic [215], They were also shown to increase the ocular bioavailability of hydrophilic drugs significantly more than liposomes. This is due to the fact that the surfactants in the niosomes act as penetrations enhancers and remove the mucous layer from the ocular surface [209]. 

Polymer-based systems offer numerous advantages, such as biocompatibility, biodegradability, and ability to incorporate functional groups for attachment of drugs. Drugs can be incorporated into the polymer matrix or in the cavity created by the polymeric architecture, from which the drug molecule can be released with an element of temporal control, and controlled pharmacokinetic profile with almost zero-order release achievable. 

Signori, F., et al. (2005), New self-assembling biocompatible-biodegradable amphiphilic block copolymers, Polymer, 46(23), 9642-9652. 

Hydrophobically modified polymers can associate in aqueous media to form micelle-like structures above their critical association concentrations (CACs). The nanosized self-aggregates were prepared using modified natural polysaccharides such as pullulan, curdlan, and glycol chitosan. The modified polysaccharides provide excellent biocompatibility, biodegradability, low immunogenicity, and biological activities. 

Besides polymers such as polylactides, waxes have the potential as biocompatible/biodegradable carriers in... 

Collagen is a natural fibrous protein found in human cartilage, connective tissue, and bone. Glutaraldehyde cross-linked bovine collagen is a sterile, biocompatible, biodegradable, purified bovine dermocollagen cross-linked with glutaraldehyde, mixed in a phosphate-buffered saline solution. 

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