Swelling and network parameters of crosslinked porous octadecyl acrylate copolymers as oil spill sorbers

Protein drugs like growth factors are promising therapeutics for damaged-tissue repair. Their local delivery often requires biomaterial carriers for achieving the therapeutic dose range while extending efficacy. In this study, polyethylene glycol (PEG) and keratin were crosslinked and used as sponge-like scaffolds (KTN-PEG) to absorb test proteins with different isoelectric points (pI): albumin (~5), hemoglobin (~7), and lysozyme (~11). The protein release kinetics was influenced by charge at physiological pH 7.4. The keratin network, with pI 5.3, electrostatically attracted lysozyme and repulsed albumin generating the release rate profile: albumin > hemoglobin > lysozyme. However, under acidic conditions (pH 4), all proteins including keratins were positively charged and consequently intermolecular repulsion altered the release hierarchy, now determined by size (MW) diffusion: lysozyme (14 kDa) > hemoglobin (64 kDa) > albumin (66 kDa). Vascular endothelial growth factor C (VEGF-C), with properties comparable to lysozyme, was absorbed into the KTN-PEG scaffold. Endothelial cells cultured on this substrate had significantly larger numbers than on scaffolds without VEGF-C suggesting that the ionically bound and retained growth factor at neutral pH indirectly increased acute cell attachment and viability. PEG and keratin based sequestrations of proteins with basic pIs are therefore a feasible strategy with potential applications for selective biologics delivery.

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“…The following properties of PEG and KTN-PEG scaffolds were quantified [ 23 , 30 – 32 ]: Q , ν e , and M c . Consider

where Q is equilibrium volume swelling ratio, V swollen is volume of absorbate and scaffold, and V dry is volume of scaffold.…”

Section: Methodsmentioning

confidence: 99%

PEG-Immobilized Keratin for Protein Drug Sequestration and pH-Mediated Delivery

Guzman

Rabbany

2016

Journal of Drug Delivery

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“…Zhou and Cho 35 and Zhou and Ha 36 reported the highest swelling uptake observed for 4-tert-butylstyrene-styrene butadiene rubber (SBR) divinylbenzene as 57.8 g g À1 polymer aer being immersed in oil solution for 48 h. The oil absorbency of 4-tert-butylstyreneethylene-propylene-diene-divinylbenzene (PBED) gra terpolymer is the highest namely 84.0 g g À1 for the treated PBED. 32 In our previous works, 12,[37][38][39] we achieved good oil uptakes, ranging from 65 up to 95 g oil per g, for crosslinked polymers based on crosslinking of alkyl acrylate homo-and copolymers by variation of the crosslinking techniques through thermal, photo and e-beam irradiation initiation techniques. In the present work we succeeded in obtaining oil sorption capacity of 90.2 g oil per g of polymer in 60 minutes.…”

Section: Discussionmentioning

confidence: 81%

“…Porous gels based on these materials have been intensively researched to evaluate the inuence of the synthesis conditions on the structural characteristics and oil absorbency. [11][12][13] However, these gels alone lack the mechanical strength and structural integrity needed for the intended application. Similarly, emulsion templating offers an alternative route for preparation of functional porous polymers; however the materials produced by this method are not necessarily ideal for operation in the intended environmental conditions.…”

Section: Introductionmentioning

confidence: 99%

Porous polymer oil sorbents based on PET fibers with crosslinked copolymer coatings

et al. 2013

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Oil sorbents-namely materials that can be used to extract oil after a spill-were fabricated from nonwoven polyethylene terephthalate (NWPET) fibers modified by the adherence of crosslinked polymer coatings to the fiber surface. The NWPET fibers, which serve as a structural support for the applied functional coatings, were produced from recycled PET (polyethylene terephthalate) bottles. The oil absorbing coatings were comprised of crosslinked homopolymers and copolymers based on octadecyl acrylate (ODA), maleic anhydride (MA), and related esters of MA. The crosslinked polymer networks were synthesized by both suspension and bulk polymerization techniques using divinylbenzene (DVB) as the crosslinking agent. Efficacy of the coated NWPET fibers as oil sorbers was determined by oil absorption tests in toluene and in 10% crude oil in toluene. Rigidity, porosity and swelling of the crosslinked polymers were evaluated and correlated to the chemical structures, composition, and reaction media. Suspension polymerization yielded the desired morphology and function, providing higher porosity and in consequence a high absorption capacity.

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“…29 Diffusion of moisture, gases or liquids across ceramic surfaces can be neglected for most purposes while such diffusion is fairly typical for polymers [30][31][32] and usually causes swelling. [33][34][35] As before, we first used TGA for evaluation of four different HTP coatings; see Fig. 6.…”

Section: Encapsulated Materialsmentioning

confidence: 99%