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Polymeric Gene Delivery Carriers for Pulmonary Diseases
Published in Severian Dumitriu, Valentin Popa, Polymeric Biomaterials, 2020
Xiang Gao, Regis R. Vollmer, Song Li
Linear PEI, which has most nitrogen in the form of secondary amines, is generated by hydrolyzing protected precursor poly(2-ethyl-2-oxazoline), which is obtained by the cationic ring-opening polymerization of 2-ethyl-2-oxazoline. Using a specially designed initiator, one could generate a monofunctional linear polymer with a unique end group introduced on one of its termini. The Zuber group has reported the synthesis of linear PEI (∼5000 Da) terminated at one end with a nucleophilic hydrazine residue, which can be used to selectively conjugate with an aldehyde-containing macromolecule, such as oxidized transferrin to form PEI–transferrin conjugate for targeted delivery of DNA (Pons et al., 2006). Through polymerization using a mono- or a bifunctional macroinitiator, followed by deprotection, PEI-macroinitiator diblocker, or PEI-macroinitiator-PEI triblocker, can be generated, respectively. Neutral polymer such as polyethylene glycol (PEG) can be incorporated to render the PEI–PEG conjugates serum resistant and less toxic while retaining excellent DNA condensation and transfection activity (Zhong et al., 2005).
Recent advancements and perspective of ciprofloxacin-based antimicrobial polymers
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Shreya Kanth, Yashoda Malgar Puttaiahgowda, Sonali Gupta, Swathi T.
The chitosan/poly(2-ethyl-2-oxazoline) films loaded with CPF was prepared by Guzel et al. to find its application in vaginal drug delivery [53]. The solvent evaporation method was employed to obtain polymeric films of chitosan (CHI) with poly(2-ethyl-2-oxazoline) (POZ), followed by addition of CPF hydrochloride solution to CHI and CHI/POZ. The prepared films with and without CPF were tested for their antibacterial activity against S. aureus and E. coli via disk-diffusion method. The films loaded with CPF exhibited inhibition zones against S. aureus ranging from 36.0 ± 1.9 mm to 46.1 ± 1.7 mm whereas better activity against E. coli with zone of inhibition ranging from 39.3 ± 2.3 mm to 42.5 ± 2.0 mm. The in vitro drug release studies were carried out for pathological vaginal conditions (pH= 3.8–4.2) and CHI/POZ films were tested using dialysis membrane in PBS solution at pH = 7.4. The CHI/POZ films showed the better release in the range of 51 ± 3% to 56 ± 2% in 4 h compared to pure CHI (not more than 45%) due to the presence of POZ in blended film. The authors have also used sheep vaginal tissues as substrate material to evaluate the mucoadhesive properties of the films and pure chitosan and the films loaded with CPF exhibited some reduction in mucoadhesive properties. Henceforth, the prepared formulated films could potentially be used in vaginal drug delivery.
Effect of end-grafted PEG conformation on the hemocompatibility of poly(styrene-b-(ethylene-co-butylene)-b-styrene)
Published in Journal of Biomaterials Science, Polymer Edition, 2019
Jianhua Lv, Jing Jin, Yuanyuan Han, Wei Jiang
Poly(ethylene glycol) (PEG) is a nontoxic, uncharged, and nonimmunogenic polymer with antibiofouling property [3, 4]. Hydrophilicity and steric repulsion of PEG endow surface with considerable hemocompatibility [5]. Grafting density and chain length of PEG are the two significant parameters to improve protein resistance and hemocompatibility [6, 7]. Different kinds of PEG conformations, such as pancaked-like, mushroom, and brushes, are formed depending on chain density [8, 9]. Polymer chains immobilized at one and both ends onto surfaces form polymer brushes with linear and looped conformations. Some researchers reported the preparation of antifouling coatings bearing polymer looped conformation using a mussel-inspired ABA triblock copolymer with catechol-anchoring groups [10] or poly[(N,N-dimethylacrylamide)15-co-(N-3,4-dihydroxyphenethyl acrylamide)2]-anchoring group [11] or looped poly-2-ethyl-2-oxazoline (PEOXA) with nitro-catechol groups [12]. However, the complicated triblock copolymers or the looped PEOXA are hard to synthesis and few publications focus on the looped conformation with two ends immobilized on plastic substrate to enhance hemocompatibility. Recently, a Monte Carlo simulation in our group reported that the surface smoothness and a dense impenetrable layer are the two significant characteristics of the looped polymer brush in resisting protein adsorption [13]. Experimentally, a mussel-inspired modification with dopamine self-polymerization is employed to modify substrate and further construct PEG with looped conformation [14].
Polyethylenimine-based nanocarriers in co-delivery of drug and gene: a developing horizon
Published in Nano Reviews & Experiments, 2018
Abbas Zakeri, Mohammad Amin Jadidi Kouhbanani, Nasrin Beheshtkhoo, Vahid Beigi, Seyyed Mojtaba Mousavi, Seyyed Ali Reza Hashemi, Ayoob Karimi Zade, Ali Mohammad Amani, Amir Savardashtaki, Esmail Mirzaei, Sara Jahandideh, Ahmad Movahedpour
Polymer chemistry has new things by business manufacturers, they produce poly(2-ethyl-2-oxazoline) with trade name Aquasolo. In addition, PEI has recently released a high degree of purity for Aquasolo, which is formed from 2-ethyl-2-oxazoline (>99.5% by GC) under compression conditions [17]. On the other hand, PEIs are polymer molecules that consist of repeating amine units and two aliphatic carbon. The branched PEI may have all the primary, secondary and tertiary amino groups, while the linear PEI has only the primary and secondary types. Besides, LPEI is solid at room temperature (near the melting point), while the BPEI is liquid (regardless of molecular weight). In addition, LPEI can be soluble in Boiling taste water with low pH, chloroform, ethanol and methanol [9,18].