High Refractive Index Inorganic–Organic Interpenetrating Polymer Network (IPN) Hydrogel Nanocomposite toward Artificial Cornea Implants

2012 ◽  
Vol 1 (7) ◽  
pp. 876-881 ◽  
Author(s):  
Quanyuan Zhang ◽  
Zheng Fang ◽  
Ye Cao ◽  
Huamao Du ◽  
Hong Wu ◽  
...  
Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4372
Author(s):  
Yu-Chi Ma ◽  
Chang-Tsung Hsieh ◽  
Yu-Hsiang Lin ◽  
Chi-An Dai ◽  
Jia-Han Li

The blindness caused by cornea diseases has exacerbated many patients all over the world. The disadvantages of using donor corneas may cause challenges to recovering eye sight. Developing artificial corneas with biocompatibility may provide another option to recover blindness. The techniques of making individual artificial corneas that fit the biometric parameters for each person can be used to help these patients effectively. In this study, artificial corneas with different shapes (spherical, aspherical, and biconic shapes) are designed and they could be made by two different hydrogel polymers that form an interpenetrating polymer network for their excellent mechanical strength. Two designed cases for the artificial corneas are considered in the simulations: to optimize the artificial cornea for patients who still wear glasses and to assume that the patient does not wear glasses after transplanting with the optimized artificial cornea. The results show that the artificial corneas can efficiently decrease the imaging blur. Increasing asphericity of the current designed artificial corneas can be helpful for the imaging corrections. The differences in the optical performance of the optimized artificial corneas by using different materials are small. It is found that the optimized artificial cornea can reduce the high order aberrations for the second case.


2014 ◽  
Vol 86 (11) ◽  
pp. 1707-1721 ◽  
Author(s):  
Ecaterina Stela Dragan

Abstract Interpenetrating polymer network (IPN) hydrogels brought distinct benefits compared to single network hydrogels like more widely controllable physical properties, and (frequently) more efficient drug loading/release. However, IPN strategy is not sufficient to design hydrogels with enhanced mechanical properties required for regenerative medicine like replacement of natural cartilage or artificial cornea. Some of the novel techniques promoted last decade for the preparation of IPN hydrogels which fulfill these requirements are discussed in the review. Among them, “double network” strategy had a strong contribution in the development of a large variety of hydrogels with spectacular mechanical properties at water content up to 90 %. Using cryogelation in tandem with IPN strategy led to composite cryogels with high mechanical properties and high performances in separation processes of ionic species. Highly stretchable and extremely tough hydrogels have been obtained by combining a covalently cross-linked synthetic network with an ionically cross-linked alginate network. IPN hydrogels with tailored mesh size have been also reported.


1994 ◽  
Vol 28 (6) ◽  
pp. 745-753 ◽  
Author(s):  
Traian V. Chirila ◽  
Sarojini Vijayasekaran ◽  
Robert Horne ◽  
Yi-Chi Chen ◽  
Paul D. Dalton ◽  
...  

2019 ◽  
Vol 9 (1) ◽  
pp. 159-173 ◽  
Author(s):  
Yunes Panahi ◽  
Afshin Gharekhani ◽  
Hamed Hamishehkar ◽  
Parvin Zakeri-Milani ◽  
Hamed Gharekhani

Purpose: In this study, we aimed to prepare an extended drug delivery formulation ofclarithromycin (CAM) based on a semi-interpenetrating polymer network (semi-IPN) hydrogel.Methods: Synthesis of semi-IPN hydrogel nanocomposite made of chitosan (CS), acrylicacid (AA), acrylamide (AAm), polyvinylpyrrolidone (PVP), and montmorillonite (MMT) wasperformed by free radical graft copolymerization method. Swelling kinetic studies were done inacidic buffer solutions of hydrochloric acid (pH = 1.2), acetate (pH = 4), and also distilled water.Also, the effects of MMT on the swelling kinetic, thermal stability, and mechanical strengthof the hydrogels were evaluated. Moreover, in vitro release behavior of CAM and its releasekinetics from hydrogels were studied in a hydrochloric acid buffer solution.Results: Fourier transform infrared spectroscopy (FTIR) results revealed that synthesis of semi-IPN superabsorbent nanocomposite and CAM incorporation into hydrogel was performed,successfully. Introducing MMT into hydrogel network not only improved its thermal stabilitybut also increased mechanical strength of the final hydrogel product. Also, in comparisonwith neat hydrogel (1270 g/g), hydrogel nanocomposite containing 13 wt% MMT exhibitedgreater equilibrium swelling capacity (1568 g/g) with lower swelling rate. In vitro drug releaseexperiments showed that CS-g-poly(AA-co-AAm)/PVP/MMT/CAM formulation possesses asustained release character over extended period of time compared with CS-g-poly(AA-co-AAm)/PVP/CAM formulation.Conclusion: In the presence of MMT, the effective life time of drug is prolonged, demonstrating asustained release property. The reason is that interlinked porous channels within superabsorbentnanocomposite network hinder penetration of aqueous solutions into hydrogel and subsequentlycause a slower drug release.


Author(s):  
Rachel Parke-Houben ◽  
Courtney H. Fox ◽  
Luo Luo Zheng ◽  
Dale J. Waters ◽  
Jennifer R. Cochran ◽  
...  

2019 ◽  
Author(s):  
Mohammad Atif Faiz Afzal ◽  
Mojtaba Haghighatlari ◽  
Sai Prasad Ganesh ◽  
Chong Cheng ◽  
Johannes Hachmann

<div>We present a high-throughput computational study to identify novel polyimides (PIs) with exceptional refractive index (RI) values for use as optic or optoelectronic materials. Our study utilizes an RI prediction protocol based on a combination of first-principles and data modeling developed in previous work, which we employ on a large-scale PI candidate library generated with the ChemLG code. We deploy the virtual screening software ChemHTPS to automate the assessment of this extensive pool of PI structures in order to determine the performance potential of each candidate. This rapid and efficient approach yields a number of highly promising leads compounds. Using the data mining and machine learning program package ChemML, we analyze the top candidates with respect to prevalent structural features and feature combinations that distinguish them from less promising ones. In particular, we explore the utility of various strategies that introduce highly polarizable moieties into the PI backbone to increase its RI yield. The derived insights provide a foundation for rational and targeted design that goes beyond traditional trial-and-error searches.</div>


2013 ◽  
Vol 28 (6) ◽  
pp. 671-676 ◽  
Author(s):  
Yu-Qing ZHANG ◽  
Li-Li ZHAO ◽  
Shi-Long XU ◽  
Chao ZHANG ◽  
Xiao-Ying CHEN ◽  
...  

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22544-22555
Author(s):  
Atefeh Safaei-Yaraziz ◽  
Shiva Akbari-Birgani ◽  
Nasser Nikfarjam

The interlacing of biopolymers and synthetic polymers is a promising strategy to fabricate hydrogel-based tissue scaffolds to biomimic a natural extracellular matrix for cell growth.


Sign in / Sign up

Export Citation Format

Share Document