Smart Polymers and Coatings Obtained by Ionizing Radiation: Synthesis and Biomedical Applications

Abstract

Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone as a result of the exposition to high-energy radiation, in which a proper microenvironment for the reaction among monomer and/or polymer and the active sites takes place, thus leading to propagation which forms side chain grafts. The modification of polymers using high-energy irradiation may be performed by the following methods: direct or simultaneous, pre-irradiation oxidative and pre-irradiation. The most frequent ones correspond to the pre-irradiation oxidative method and the direct one. Radiation-grafting has many advantages over conventional methods considering that it does not require catalyst nor additives to initiate the reaction, and in general, no changes on the mechanical properties with respect to the pristine polymeric matrix are observed. This chapter focused on the synthesis of smart polymers and coatings obtained by the use of gamma radiation. In addition, diverse applications of these materials in the biomedical field are also reported.

Role of Cross-Linking Process on the Performance of PMMA

“…Table 3 shows the most important monomers and their common abbreviations that predominantly used as cross-linkers or cross-Linking agents in such cross-linking process for PMMA. Degree of cross-linking is controlled by highenergy ionizing radiation, gamma, or x-ray and their radiation dose [29]. …”

A Review of Overcome the Side Effect of Digestion Process on the Drugs

“…Natural polymers such as starch and their derivatives refer to a group of polymers widely used in the biomedical and pharmaceutical fields for controlled release application. Several polysaccharides such as starch, cellulose and chitosan have been used extensively either alone or in combination with their modified form to regulate drug release from many drug delivery systems [13], [14]. It has been found that the best types of polymers used in the preparation of polymer drugs is the natural polymers, such as polysaccharide (starch, cellulose, chitosan).…”

Surface functionalisation of poly-APO-b-polyol ester cross-linked copolymers as core–shell nanoparticles for targeted breast cancer therapy

“…The application of this process offers various advantages, such as easy set-up, inexpensive, less toxic, and an environmentally-friendly process. Therefore, numerous research works have applied RAFT polymerisation for the development of polymeric nanomaterials using gamma radiation 6 , 7 , 9 – 11 .

Figure 1 ( a ) The mechanism of reversible addition fragmentation chain transfer (RAFT) polymerisation under thermal, UV, or ionising radiation in the chain extension of macro-CTA agent and in the formation of block copolymer 9 ; ( b ) the general chemical structure and products of APO; ( c ) the general chemical structure and products of polyol ester; ( d ) FTIR of the (i) APO and (ii) polyol ester.

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