Hierarchically structured microgels of SPIONs, nanofibers, and alginate for copper ion removal

Mallinath S. Birajdar,이종휘 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.77 No.-

Microgels have been developed for various practical applications such as heavy metal removal. However,their internal structures are difficult to control for a specific application. This study, for thefirst time,confirms that a hierarchical structure improves the ability of microgels in heavy metal ion removal. Superparamagnetic iron oxide nanoparticles (SPIONs) were incorporated into polylactic acid nanofiberswhich were then incorporated into alginate microgels, both of which have metal removal capability. Acombination of electrospinning and spraying was used to prepare the microgels. Thefibers outside themicrogels were selectively dissolved out in a subsequent step. Thefiber density inside the microgelscould be controlled by the electrospinning time. This SPION-loaded nanofiber-entrapped alginatemicrogel showed outstanding Cu2+ ion adsorption compared to ones without SPIONs or nanofibers. Thishierarchical microarchitecture of microgel couldfind various applications in thefields of futureenvironmental applications.

Blood-clotting mimetic behavior of biocompatible microgels

Mallinath S. Birajdar,Kantappa S. Halake,이종휘 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.63 No.-

Recent advances in hydrogel chemistry have led to the development of various soft materials capable of self-healing. Nevertheless, their self-healing capabilities are primitive compared to the responsive and adaptive strategies of blood clotting and wound healing in the human body. We developed a novel microgel system that mimics the process of blood clotting. Electrospun polylactic acid (PLA) fibers were entrapped inside the microgels of a hyaluronic acid conjugate with hesperidin side groups crosslinked by Fe ions; the resulting hydrogels showed fast self-healing and magnetic responsive properties. By applying an external magnetic field, which mimicked blood flow, the microgels successfully aggregated at target sites, like platelets. The aggregates were stable, as demonstrated by resistance to sonication for 30 min, and their moduli spanned tens to hundreds of kPa, demonstrating the mechanical integrity of the artificial clots. Like fibrin, the PLA fibers successfully strengthened the aggregates due to formation of uniform fiber-reinforced hydrogels; the artificial clots containing fibers had a 300% improved modulus and 50% increased hardness relative to the hydrogels without fibers. This unique intelligent system can be utilized in future self-healing systems, delivery systems, and devices with microfluidic channels.

Surface conjugation of poly (dimethyl siloxane) with itaconic acid-based materials for antibacterial effects

Birajdar, Mallinath S.,Cho, Hyunjoo,Seo, Youngmin,Choi, Jonghoon,Park, Hansoo Elsevier BV * North-Holland 2018 Applied Surface Science Vol.437 No.-

<P><B>Abstract</B></P> <P>Poly (dimethyl siloxane) (PDMS) is widely used in various biomedical applications. However, the PDMS surface is known to cause bacterial adhesion and protein absorption issues due to its high hydrophobicity. Therefore, the development of antibacterial and anti-protein products is necessary to prevent these problems. In this study, to improve its antibacterial property and prevent protein adsorption, PDMS surfaces were conjugated with itaconic acid (IA) and poly (itaconic acid) (PIA) via a chemical method. Additionally, IA and PIA were physically blended with PDMS to compare the antibacterial properties of these materials with those of the chemically conjugated PDMS surfaces. The successful synthesis of the PIA polymer structure was confirmed by proton nuclear magnetic resonance (<SUP>1</SUP>H NMR) spectroscopy. The successful conjugation of IA and PIA on PDMS was confirmed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), water contact angle measurements, and microbicinchoninic acid (BCA) protein assay analyses. The PDMS surfaces functionalized with IA and PIA by the conjugation method better prevented protein adsorption than the bare PDMS. Therefore, these surface-conjugated PDMS can be used in various biomedical applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A best bacterial anti-adhesion system was developed based on itaconic acid hydrophilic materials via chemical conjugation and physical blending methods. </LI> <LI> Itaconic acid (IA) and poly (itaconic acid) (PIA) were conjugated chemically onto PDMS surfaces to improve antibacterial activity. </LI> <LI> The PDMS surfaces functionalized with IA and PIA increased contact angle, prevented protein adsorption than the bare PDMS and also did not show cytotoxicity. </LI> <LI> The best bacterial anti-adhesion effect was observed for the high-concentration PIA-conjugated PDMS surface prepared by the combined method. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Blood-clotting mimetic behavior of biocompatible microgels

Birajdar, Mallinath S.,Halake, Kantappa S.,Lee, Jonghwi THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.63 No.-

<P><B>Abstract</B></P> <P>Recent advances in hydrogel chemistry have led to the development of various soft materials capable of self-healing. Nevertheless, their self-healing capabilities are primitive compared to the responsive and adaptive strategies of blood clotting and wound healing in the human body. We developed a novel microgel system that mimics the process of blood clotting. Electrospun polylactic acid (PLA) fibers were entrapped inside the microgels of a hyaluronic acid conjugate with hesperidin side groups crosslinked by Fe ions; the resulting hydrogels showed fast self-healing and magnetic responsive properties. By applying an external magnetic field, which mimicked blood flow, the microgels successfully aggregated at target sites, like platelets. The aggregates were stable, as demonstrated by resistance to sonication for 30min, and their moduli spanned tens to hundreds of kPa, demonstrating the mechanical integrity of the artificial clots. Like fibrin, the PLA fibers successfully strengthened the aggregates due to formation of uniform fiber-reinforced hydrogels; the artificial clots containing fibers had a 300% improved modulus and 50% increased hardness relative to the hydrogels without fibers. This unique intelligent system can be utilized in future self-healing systems, delivery systems, and devices with microfluidic channels.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A blood-clotting mimetic system was developed based on fast self-healing and magnetic responsive behavior. </LI> <LI> Novel biodegradable microgels mimic platelets. </LI> <LI> Electrospun fibers entrapped in microgels mimic fibrins. </LI> <LI> They can form stable artificial clots of moduli spanned tens to hundreds of kPa. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The novel microgels formed an artificial clot upon application of a magnetic field; this behavior can be utilized as a novel self-healing process or to prepare fiber-reinforced composites.</P> <P>[DISPLAY OMISSION]</P>

Inhibition of Capsular Contracture of Poly (Dimethyl Siloxane) Medical Implants by Surface Modification with Itaconic Acid Conjugated Gelatin

Mallinath S. Birajdar,Byung Hwi Kim,Chanutchamon Sutthiwanjampa,강신혁,Chan Yeong Heo,Hansoo Park 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.89 No.-

Silicone implants have been widely used for the fabrication of medical devices and implants due to theirbiocompatibility and inert properties. However, the contact with biologicalfluids and the ensuing surfaceadsorption of proteins often lead to the formation of biofilms such as capsular contracture (CC), requiringthe removal of implants. Therefore, there has been an urgent demand for surface modification withbiomaterials having anti-inflammatory, anti-microbial, and anti-fibrotic activities to prevent CC onsilicone implants. Here, Itaconic acid (IA) conjugated with PDMS (IA-PDMS) and IA-conjugated gelatinpolymer (IA-GTpoly) conjugated with PDMS (IA-GTpoly-PDMS) with various concentrations wereexamined as a candidate for inhibition of CC on the surface of PDMS. The IA-PDMS and IA-GTpoly-PDMSsurfaces showed lower inflammation, in vivo capsule thickness, and collagen density than the bare PDMSdid. Our results demonstrated the significant potential of IA based materials for surface modification ofPDMS to develop biocompatible surfaces for various biomedical devices.

Natural Bio-Based Monomers for Biomedical Applications: a review

Mallinath S. Birajdar,Haejin Joo,고원건,박한수 한국생체재료학회 2021 생체재료학회지 Vol.25 No.2

In recent years, synthetic and semi-synthetic polymer materials have been widely used in various applications. Especially concerning biomedical applications, their biocompatibility, biodegradability, and non-toxicity have increased the interest of researchers to discover and develop new products for the well-being of humanity. Among the synthetic and semi-synthetic materials, the use of natural bio-based monomeric materials presents a possible novel avenue for the development of new biocompatible, biodegradable, and non-toxic products. The purpose of this article is to review the information on the role of natural bio-based monomers in biomedical applications. Increased eco-friendliness, biocompatibility, biodegradability, non-toxicity, and intrinsic biological activity are some of the attributes which make itaconic, succinic, citric, hyaluronic, and glutamic acids suitable potential materials for biomedical applications. Herein, we summarize the most recent advances in the field over the past ten years and specifically highlight new and interesting discoveries in biomedical applications.

Electrospun carbon nanofibers with core-shell structure as counter electrode for dye-sensitized solar cells

김건희,박소현,( Mallinath S. Birajdar ),이종휘,홍성철 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Counter electrode (CE) for dye-sensitized solar cells (DSSCs) from carbon materials has been widely studied. In this study, core-shell carbon nanofibers were prepared employing poly(acrylonitrile-co-itaconic acid), polyacrylonitrile and Pt precursors following electrospinning and carbonization procedures, affording carbon materials with high electrical conductivity, catalytic activity, surface area, and corrosion resistance. The resulting carbon nanofiber mats were introduced into DSSCs as a CE. The DSSCs with the carbon nanofiber CE exhibited good performances including high solar energy conversion efficiency (η) value compared to that with conventional carbon CE.

Core/shell structured carbon nanofiber/platinum nanoparticle hybrid web as a counter electrode for dye-sensitized solar cell

김건희,박소현,Mallinath S. Birajdar,이종휘,홍성철 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.52 No.-

Core/shell structured carbon nanofiber/platinum nanoparticle (Pt NP) hybrid web was prepared andapplied to counter electrode (CE) of dye-sensitized solar cell. Nanofibers (NFs) composed ofpolyacrylonitrile (co)polymer and Pt precursors werefirst prepared by coaxial electrospinning. A seriesof thermal treatment procedures afforded simultaneous transformations of the precursors to carbonnanofiber (CNF) web with Pt NPs in the shell layer. This spatial distribution of Pt NPs in CNF increased theelectrocatalytic activity of the CNF web. The CE exhibited a low charge transfer resistance at the interfacebetween CE and electrolyte, demonstrating synergistic combination of Pt NPs and the CNF.

Preparation of hydrogel nanofibers based on chitosan and PEG

정승환,이종휘,( Mallinath S Birajdar ) 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Chitosan is a natural biopolymer, which is often considered as a poorly spinnable polymer. It is widely applied in the biomedical areas after crosslinking, because of its outstanding biocompatible properties. To utilize the high surface area of nanofibers and the high water swelling property of hydrogels together, hydrogel nanofibers based on chitosan were developed in here. Using an aqueous acetic acid solution of chitosan and other monomers, nanofibrous nonwoven fabric was first prepared, followed by UV crosslinking. After crosslinking, hydrogel nanofibers were stable enough in water. The amount of the leaching-out materials in water for a week could be minimized down to 1.3 wt%. The morphology of chitosan/PEG mat was examined by optical microscope and scanning electron micrographs, which showed uniform ultrafine fibers with diameters from 100 nm to 500 nm. These biocompatible hydrogel materials of high surface area could be useful in various future applications such as sensors, waste scavenging, and catalysis as interesting matrices.

Structure controlled carbon nanofiber mat as a counter electrode for dye-sensitized solar cells

( Ghorpade Ravindra ),김건희,박소현,( Mallinath S. Birajdar ),이종휘,홍성철 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Carbonaceous materials have been investigated as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). In this study, nanofiber mats composed of polyacrylonitrile (co)polymer and Pt precursors were prepared by electrospinning method. Series of thermal treatment on the mats, such as thermal oxidative stabilization, carbonization and graphitization, afforded structure-controlled carbon nanofiber/Pt mats with high electrical conductivity, large surface area and high catalytic activity. The carbon nanofiber/Pt mat was introduced in DSSC as a CE by using adhesives without major structural deformations. The DSSC exhibited good performance including high energy conversion efficiency, which was comparable to that of conventional DSSC with all Pt CE.