title: Biocompatible Hydroxylated Boron Nitride Nanosheets/Poly(vinyl alcohol) Interpenetrating Hydrogels with Enhanced Mechanical and Thermal Responses.
abstract: Poly(vinyl alcohol) (PVA) hydrogels with tissue-like viscoelasticity, excellent biocompatibility, and high hydrophilicity have been considered as promising cartilage replacement materials. However, lack of sufficient mechanical properties is a critical barrier to their use as load-bearing cartilage substitutes. Herein, we report hydroxylated boron nitride nanosheets (OH-BNNS)/PVA interpenetrating hydrogels by cyclically freezing/thawing the aqueous mixture of PVA and highly hydrophilic OH-BNNS (up to 0.6 mg/mL, two times the highest reported so far). Encouragingly, the resulting OH-BNNS/PVA hydrogels exhibit controllable reinforcements in both mechanical and thermal responses by simply varying the OH-BNNS contents. Impressive 45, 43, and 63% increases in compressive, tensile strengths and Young's modulus, respectively, can be obtained even with only 0.12 wt% (OH-BNNS:PVA) OH-BNNS addition. Meanwhile, exciting improvements in the thermal diffusivity (15%) and conductivity (5%) can also be successfully achieved. These enhancements are attributed to the synergistic effect of intrinsic superior properties of the as-prepared OH-BNNS and strong hydrogen bonding interactions between the OH-BNNS and PVA chains. In addition, excellent cytocompatibility of the composite hydrogels was verified by cell proliferation and live/dead viability assays. These biocompatible OH-BNNS/PVA hydrogels are promising in addressing the mechanical failure and locally overheating issues as cartilage substitutes and may also have broad utility for biomedical applications, such as drug delivery, tissue engineering, biosensors, and actuators.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.|Institute for Sports Research, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Lin
authors.identifier: 0000-0003-2282-5129
authors.initials: L
authors.lastname: Jing
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Hongling
authors.identifier: 0000-0002-2292-1949
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Roland Yingjie
authors.initials: RY
authors.lastname: Tay
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 119260, Singapore.
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.affiliation: Temasek Laboratories@NTU , 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Siu Hon
authors.initials: SH
authors.lastname: Tsang
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Olivier
authors.identifier: 0000-0003-0269-3624
authors.initials: O
authors.lastname: Cometto
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Jinjun
authors.initials: J
authors.lastname: Lin
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.|School of Electrical and Electronic Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Edwin Hang Tong
authors.initials: EHT
authors.lastname: Teo
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.|Institute for Sports Research, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Alfred Iing Yoong
authors.initials: AIY
authors.lastname: Tok
keywords: boron nitride nanosheets; cytocompatibility; hydrogel; hydroxyl-functionalization; mechanical enhancement; thermal response