| 1. |
- Gustafsson, Olof, et al.
(author)
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Scalable and Sustainable Total Pathogen Removal Filter Paper for Point-of-Use Drinking Water Purification in Bangladesh
- 2019
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In: ACS Sustainable Chemistry and Engineering. - : AMER CHEMICAL SOC. - 2168-0485. ; 7:17, s. 14373-14383
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Journal article (peer-reviewed)abstract
- This article describes for the first time the full cycle of development from raw material cultivation to real-life application of a truly sustainable and scalable filter paper material intended for point-of-use drinking water purification in Bangladesh. The filter paper, featuring tailored pathogen removal properties, is produced from nanocellulose extracted from Pithophora green macroalgae, growing locally in Bangladesh, a new unexploited resource that can address a global problem. We demonstrate that the Pithophora cellulose filter paper can be used as a total pathogen barrier to remove all types of infectious viruses and bacteria from water. The performance of the filter is validated using surrogate latex nanobeads, in vitro model viruses, and real-life water samples collected from the Turag River and Dhanmondi Lake in Dhaka, Bangladesh. Access to clean drinking water is a persistent problem in Bangladesh, affecting tens of millions of people every day. The mortality rate due to water-borne diarreal infections, including viral infections, among susceptible population groups, especially among children under age of 5, is still very high. The proposed solution can dramatically improve the quality of lives for millions of people in the entire Southeast Asian region including and beyond the borders of Bangladesh.
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| 2. |
- Tummala, Gopi Krishna, 1986-, et al.
(author)
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Biocompatibility of nanocellulose-reinforced PVA hydrogel with human corneal epithelial cells for Ophthalmic applications
- 2019
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In: Journal of Functional Biomaterials. - : MDPI AG. - 2079-4983. ; 10:3
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Journal article (peer-reviewed)abstract
- Transparent composite hydrogel in the form of a contact lens made from poly(vinyl alcohol) (PVA) and cellulose nanocrystals (CNCs) was subjected to in vitro biocompatibility evaluation with human corneal epithelial cells (HCE-2 cells). The cell response to direct contact with the hydrogels was investigated by placing the samples on top of confluent cell layers and evaluating cell viability, morphology, and cell layer integrity subsequent to 24 h culture and removal of the hydrogels. To further characterize the lens-cell interactions, HCE-2 cells were seeded on the hydrogels, with and without simulated tear fluid (STF) pre-conditioning, and cell viability and morphology were evaluated. Furthermore, protein adsorption on the hydrogel surface was investigated by incubating the materials with STF, followed by protein elution and quantification. The hydrogel material was found to have affinity towards protein adsorption, most probably due to the interactions between the positively charged lysozyme and the negatively charged CNCs embedded in the PVA matrix. The direct contact experiment demonstrated that the physical presence of the lenses did not affect corneal epithelial cell monolayers in terms of integrity nor cell metabolic activity. Moreover, it was found that viable corneal cells adhered to the hydrogel, showing the typical morphology of epithelial cells and that such response was not influenced by the STF pre-conditioning of the hydrogel surface. The results of the study confirm that PVA-CNC hydrogel is a promising ophthalmic biomaterial, motivating future in vitro and in vivo biocompatibility studies.
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| 3. |
- Tummala, Gopi Krishna, 1986-, et al.
(author)
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Role of Solvent on Structure, Viscoelasticity and Mechanical Compressibility in Nanocellulose-Reinforced Poly(vinyl alcohol) Hydrogels
- 2019
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In: Journal of Applied Polymer Science. - : Wiley. - 0021-8995 .- 1097-4628. ; 136:6
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Journal article (peer-reviewed)abstract
- Cellulose nanocrystals (CNCs) reinforced polyvinyl alcohol (PVA)‐based hydrogels with high water content and tunable mechanical properties that can be molded in to any desired shape are presented in this work. Freeze thawing of PVA‐CNC solutions in a mixed solvent system of dimethyl sulfoxide and water enabled to produce a set of physically crosslinked hydrogels with tunable mechanical properties. It was observed that the composition of the solvent altered the mechanical properties and network structure in the hydrogel systems. Differential scanning calorimetry was used to understand the thermal events behind solvent effect on the properties of the hydrogel. Optical microscopy results suggest that these hydrogels possess a macroporous structure. Furthermore, dynamic viscoelastic analysis and axial compression tests have shown that the viscoelastic and mechanical compression properties of the hydrogels improved upon reinforcement with CNC. Overall, the hydrogel enjoys appealing properties as a synthetic biomaterial for soft tissue applications.
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