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Mor S, Yadav R, Bhakuni K, Rawat P, Bisht M, Deenadayalu N, Venkatesu P. Unraveling the Role of Deep Eutectic Solvents with Varying Hydrogen-Bond Acceptors on the Thermoresponsive Polymer Poly( N-isopropylacrylamide). J Phys Chem B 2024. [PMID: 38683962 DOI: 10.1021/acs.jpcb.4c00888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Deep eutectic solvents (DESs) have emerged as promising tools for crafting polymeric materials across diverse domains. This study delves into the impact of a series of DESs on the phase behavior of poly(N-isopropylacrylamide) (PNIPAM) in aqueous environments, presenting compelling insights into their performance. Specifically, we explore the conformational phase behavior of PNIPAM in the presence of four distinct lactic acid (LA)-based DESs: LA-betaine (LA-BET), LA-proline (LA-PRO), LA-choline chloride (LA-CC), and LA-urea (LA-U). By maintaining a consistent hydrogen-bond donor (HBD) while varying the hydrogen-bond acceptor (HBA), we unravel how different DES compositions modulate the phase transition behavior of PNIPAM. Our findings underscore the profound influence of DESs comprising LA as the HBD and diverse HBAs-BET, PRO, CC, and U on the thermoresponsive behavior of PNIPAM. Employing spectroscopic techniques such as ultraviolet-visible (UV-vis) spectroscopy, steady-state fluorescence, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), ζ-potential, and transmission electron microscopy (TEM), we elucidate the preferential interactions between the HBA groups within DESs and the hydration layer of PNIPAM. Notably, temperature-dependent DLS analyses reveal a discernible decrease in the lower critical solution temperature (LCST) of PNIPAM with increasing DES concentration, ultimately disrupting the hydrogen-bond interactions and resulting in early hydrophobic collapse of the polymer, which can be clearly seen in the TEM micrographs. Furthermore, the formation of polymer composites within the mixed system leads to notable alterations in the physiochemical properties of PNIPAM, as evidenced by shifts in its LCST value in the presence of DESs. This perturbation disrupts hydrogen-bond interactions, inducing hydrophobic collapse of the polymers, a phenomenon vividly captured in TEM micrographs. In essence, our study sheds new light on the pivotal role of varying HBA groups within DESs in modulating the conformational transitions of PNIPAM. These insights not only enrich our fundamental understanding but also hold immense promise for the development of smart polymeric systems with multifaceted applications spanning bioimaging, biomedical science, polymer science, and beyond.
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Affiliation(s)
- Sanjay Mor
- Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Ritu Yadav
- Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Kavya Bhakuni
- Department of Chemistry, St. Stephen's College, University of Delhi, Delhi 110007, India
| | - Pradeep Rawat
- Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Meena Bisht
- Department of Chemistry, Sri Venkateswara College, University of Delhi, Delhi 110007, India
| | - Nirmala Deenadayalu
- Department of Chemistry, Durban University of Technology, Durban4000, South Africa
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Tinku, Prajapati AK, Choudhary S. Physicochemical insights into the micellar delivery of doxycycline and minocycline to the carrier protein in aqueous environment. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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Yadav R, Kumar K, Kumar S, Mor S, Venkatesu P. Smart Anisotropic Colloidal Composites: A Suitable Platform for Modifying the Phase Transition of Diblock Copolymers by Gold Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:4809-4818. [PMID: 36944025 DOI: 10.1021/acs.langmuir.3c00181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Surface modification of metallic nanoparticles (NPs) by stimuli-responsive polymers is a benign method to prepare smart colloidal composites which tune the characteristic properties of individual systems. The temperature-dependent transition of diblock copolymer poly(N-isopropylacrylamide)-block-poly(N-vinylcaprolactam) (PNIPMA-b-PVCL) synthesized using reversible addition-fragmentation chain transfer polymerization was studied by incorporating anisotropic gold NPs (AGPs) such as spheres (AuNSs), rods (AuNRs), cubes (AuNCs), and rhombic dodecahedrals (AuRDs). Shape-dependent physiochemical properties of nanostructures alter the lower critical solution temperature (LCST) of the chemical inhomogeneous diblock copolymer. Heterogeneous nucleation of AuNPs was facilitated by seed-mediated synthesis for incorporating uniformity. In the mixed system, the presence of PNIPAM-b-PVCL modifies the surface of AGPs through physisorption which is supported by transmission electron microscopy and field emission scanning electron microscopy showing the NPs embedding in the polymeric matrix. Furthermore, steady state fluorescence spectroscopy and Fourier transform infrared spectroscopy were performed to examine the phase transition behavior of PNIPAM-b-PVCL in AGPs. The formation of a smart polymer nanocomposite alters the physiochemical properties of the diblock copolymer as demonstrated from the variation of LCST in the dynamic light scattering measurement. Henceforth, functionalizing the surfaces of AGPs with a thermoresponsive diblock copolymer provides combinatorial benefits in the properties of smart polymeric colloidal systems with potential applications in bioimaging and drug delivery.
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Affiliation(s)
- Ritu Yadav
- Department of Chemistry, University of Delhi, Delhi-110 007, India
| | - Krishan Kumar
- Department of Chemistry, University of Delhi, Delhi-110 007, India
| | - Sumit Kumar
- Department of Chemistry, University of Delhi, Delhi-110 007, India
- Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Sanjay Mor
- Department of Chemistry, University of Delhi, Delhi-110 007, India
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Umapathi R, Kumar K, Ghoreishian SM, Rani GM, Park SY, Huh YS, Venkatesu P. Effect of Imidazolium Nitrate Ionic Liquids on Conformational Changes of Poly( N-vinylcaprolactam). ACS OMEGA 2022; 7:39742-39749. [PMID: 36385857 PMCID: PMC9648054 DOI: 10.1021/acsomega.2c03650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Detailed information about molecular interactions and conformational changes of polymeric components in the presence of ionic liquids (ILs) is essential for designing novel polymeric ionic liquid-based biomaterials. In biomaterials science and technology, thermoresponsive polymers (TRPs) are widely viewed as potential candidates for the fabrication of biorelated medical devices. Here, we synthesized thermoresponsive poly(N-vinyl-caprolactam) (PVCL) polymer and investigated the effects of imidazolium-based ILs (1-ethyl-3-methyl imidazolium nitrate and 1-butyl-3-methylimidazolium nitrate) with common anion and different cations on the phase transition behavior of PVCL aqueous solution. The impact of ILs on the phase transition behavior of PVCL was monitored by using UV-visible absorption spectra, steady-state fluorescence spectroscopy, thermal fluorescence spectroscopy, and temperature dependent dynamic light scattering. Results showed significant changes in the absorbance, molecular interactions, agglomeration, and coil to globule transition behaviors of PVCL in the presence of two ILs. PVCL aqueous solution showed significant conformational changes after the addition of ILs.
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Affiliation(s)
- Reddicherla Umapathi
- NanoBio
High-Tech Materials Research Center, Department of Biological Sciences
and Bioengineering, Inha University, Incheon 22212, Republic of Korea
| | - Krishan Kumar
- NanoBio
High-Tech Materials Research Center, Department of Biological Sciences
and Bioengineering, Inha University, Incheon 22212, Republic of Korea
- Department
of Chemistry, University of Delhi, Delhi 110 007, India
| | - Seyed Majid Ghoreishian
- NanoBio
High-Tech Materials Research Center, Department of Biological Sciences
and Bioengineering, Inha University, Incheon 22212, Republic of Korea
| | | | - So Young Park
- NanoBio
High-Tech Materials Research Center, Department of Biological Sciences
and Bioengineering, Inha University, Incheon 22212, Republic of Korea
| | - Yun Suk Huh
- NanoBio
High-Tech Materials Research Center, Department of Biological Sciences
and Bioengineering, Inha University, Incheon 22212, Republic of Korea
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Umapathi R, Kumar K, Majid Ghoreishian S, Mohana Rani G, Young Park S, Suk Huh Y, Venkatesu P. Tunnelling the structural insights between poly(N-isopropylacrylamide) and imidazolium sulfate ionic liquids. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Umapathi R, Kumar K, Ghoreishian SM, Rani GM, Huh YS, Venkatesu P. Interactions between a biomedical thermoresponsive polymer and imidazolium-based ionic liquids: A comprehensive biophysical investigation. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128619] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Kumar K, Venkatesu P. Role of protein-copolymer assembly in controlling micellization process of amphiphilic triblock copolymer. J Colloid Interface Sci 2022; 608:2142-2157. [PMID: 34758421 DOI: 10.1016/j.jcis.2021.10.117] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/20/2021] [Accepted: 10/19/2021] [Indexed: 11/29/2022]
Abstract
HYPOTHESIS Triblock copolymer poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG) forms a well-known micellar assembly at a particular temperature. Apart from regular assembly within the copolymer, it is crucial to explore additional assembly behaviour via simple exposure of proteins which unveils biased interactions with blocks of copolymer. The current work focuses on the examination of Pluronic F108 i.e. PEG-PPG-PEG with two different proteins i.e. α-chymotrypsin (CT) and lysozyme (LSZ), aiming at probing the critical micellization temperature (CMT) and molecular level interactions. EXPERIMENTS Potential role of protein-copolymer assembly formation at a particular concentration of protein in modulating CMT was shown by a systematic experimental approach combined with a series of physicochemical methods. The sophisticated multiple techniques include fluorescence spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, dynamic light scattering (DLS), zeta potential measurements, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, molecular docking studies were also employed to correlate theoretical insights with experimental findings. FINDINGS CT and LSZ decrease CMT in regular concentration-dependent manner except for particular concentration (1.5 mg/mL) of LSZ which shows anomalous behaviour in steady-state fluorescence spectroscopy, temperature dependent fluorescence spectroscopy, Raman spectroscopy and DLS measurements. SEM and TEM results clearly reveal protein-copolymer assembly formation. The assembled structure has different biophysical properties. Docking studies elucidate several bio macromolecular interactions which can be involved in assembly formation. Based on obtained results from biophysical techniques mechanism of CMT variation was deduced. Obtained results can be useful in biosensors and targeted drug delivery systems.
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Affiliation(s)
- Krishan Kumar
- Department of Chemistry, University of Delhi, Delhi 110 007, India
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Kumar S, Kumar K, Yadav R, Kukutla P, Devunuri N, Deenadayalu N, Venkatesu P. Understanding the close encounter of heme proteins with carboxylated multiwalled carbon nanotubes: a case study of contradictory stability trend for hemoglobin and myoglobin. Phys Chem Chem Phys 2021; 23:19740-19751. [PMID: 34525143 DOI: 10.1039/d1cp02167b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon nanotubes (CNTs) are one of the unique and promising nanomaterials that possess plenty of applications, such as biosensors, advanced drug delivery systems and biotechnology. CNTs bind rapidly with proteins, which result in the formation of a protein coating layer known as a "protein corona" around the surface of the nanomaterial. This hinders their applications as a drug carrier and influences the properties of biological macromolecules. The present work focuses on studying the thermal stability and molecular level interactions of two heme proteins, hemoglobin (Hb) and myoglobin (Mb), in the presence of carboxylated functionalized multi-walled CNTs (CA-MWCNTs). Through the current study, the following steps have been taken to distinguish the biocompatibility of the hydrophilic surface CA-MWCNTs for heme proteins via a series of spectroscopic techniques and differential scanning calorimetry (DSC). UV-Visible and steady-state fluorescence spectroscopy were used to reveal changes in the aromatic amino acid residues of heme proteins upon the addition of CA-MWCNTs. Circular dichroism spectroscopy (CD) shows the alteration in the native structure of proteins in the presence of the nanomaterial. A tremendous increase in the size of the protein CA-MWCNTs system is observed in dynamic light scattering (DLS), which clearly manifests the protein corona formation. Unexpectedly, both proteins interact differently with CA-MWCNTs, which is observed in CD spectroscopy and DSC. In the presence of CA-MWCNTs, an increase in the transition temperature (Tm) was observed for Hb, while the Tm value decreases for Mb. Different interactions with proteins at the molecular scale may be the reason for this unexpected behavior. Henceforth, the present results can help in the design of the next-generation drug carrier nanomaterials with the idea of the heme protein corona formation prior to development.
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Affiliation(s)
- Sumit Kumar
- Department of Chemistry, University of Delhi, Delhi-110 007, India.
| | - Krishan Kumar
- Department of Chemistry, University of Delhi, Delhi-110 007, India.
| | - Ritu Yadav
- Department of Chemistry, University of Delhi, Delhi-110 007, India.
| | - Prasanna Kukutla
- Department of Chemistry, University of Delhi, Delhi-110 007, India. .,Vignan's Foundation for Science, Technology and Research (VFSTR) Deemed to be University, Vadlamudi, Guntur-522 213, Andhra Pradesh, India
| | - Nagaraju Devunuri
- Vignan's Foundation for Science, Technology and Research (VFSTR) Deemed to be University, Vadlamudi, Guntur-522 213, Andhra Pradesh, India
| | - Nirmala Deenadayalu
- Department of Chemistry, Durban University of Technology, Durban-4000, South Africa
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Kumar K, Umapathi R, Ramesh K, Hwang SK, Lim KT, Huh YS, Venkatesu P. Biological Stimuli-Induced Phase Transition of a Synthesized Block Copolymer: Preferential Interactions between PNIPAM- b-PNVCL and Heme Proteins. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:1682-1696. [PMID: 33492958 DOI: 10.1021/acs.langmuir.0c02900] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The beguiling world of functional polymers is dominated by thermoresponsive polymers with unique structural and molecular attributes. Limited work has been reported on the protein-induced conformational transition of block copolymers; furthermore, the literature lacks a clear understanding of the influence of proteins on the phase behavior of thermoresponsive copolymers. Herein, we have synthesized poly(N-isopropylacrylamide)-b-poly(N-vinylcaprolactam) (PNIPAM-b-PNVCL) by RAFT polymerization using N-isopropylacrylamide and N-vinylcaprolactam. Furthermore, using various biophysical techniques, we have explored the effect of cytochrome c (Cyt c), myoglobin (Mb), and hemoglobin (Hb) with varying concentrations on the aggregation behavior of PNIPAM-b-PNVCL. Absorption and steady-state fluorescence spectroscopy measurements were performed at room temperature to examine the copolymerization effect on fluorescent probe binding and biomolecular interactions between PNIPAM-b-PNVCL and proteins. Furthermore, temperature-dependent fluorescence spectroscopy and dynamic light scattering studies were performed to get deeper insights into the lower critical solution temperature (LCST) of PNIPAM-b-PNVCL. Small-angle neutron scattering (SANS) was also employed to understand the copolymer behavior in the presence of heme proteins. With the incorporation of proteins to PNIPAM-b-PNVCL aqueous solution, LCST has been varied to different extents owing to the preferential, molecular, and noncovalent interactions between PNIPAM-b-PNVCL and proteins. The present study can pave new insights between heme proteins and block copolymer interactions, which will help design biomimetic surfaces and aid in the strategic fabrication of copolymer-protein bioconjugates.
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Affiliation(s)
- Krishan Kumar
- Department of Chemistry, University of Delhi, Delhi 110 007, India
| | - Reddicherla Umapathi
- NanoBio High-Tech Materials Research Center, Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Kalyan Ramesh
- Department of Display Engineering, Pukyong National University, Busan 48513, Republic of Korea
| | - Seung-Kyu Hwang
- NanoBio High-Tech Materials Research Center, Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Kwon Taek Lim
- Department of Display Engineering, Pukyong National University, Busan 48513, Republic of Korea
| | - Yun Suk Huh
- NanoBio High-Tech Materials Research Center, Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
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Kumar K, Mogha NK, Yadav R, Venkatesu P. Insulin-induced conformational transition of fluorescent copolymers: a perspective of self-assembly between protein and micellar solutions of smart copolymers. Phys Chem Chem Phys 2020; 22:9573-9586. [PMID: 32322851 DOI: 10.1039/d0cp00645a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Synthesizing and understanding phase transition behavior of novel block copolymers is very crucial for fabricating next generation of smart materials with foreseeable applications. In this regard, we synthesized three random (r) copolymers of poly(N-vinyl-caprolactam) (PVCL) and poly(2-dimethyl amino ethyl methacrylate) (PDMAEMA) with varying percentages of each block and characterized them using nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) patterns, time-resolved fluorescence spectroscopy, and atomic force microscopy (AFM). Synthesized copolymers i.e. PVCL30-PDMAEMA70, PVCL50-PDMAEMA50 and PVCL70-PDMAEMA30 have fluorescence properties, which were confirmed by time-resolved fluorescence spectra and emission spectra, and emission bands were observed at ∼310, ∼435 and ∼424 nm, respectively. The fluorescence lifetime for PVCL50-PDMAEMA50 is larger than those of the other two copolymers suggesting a slow decay of the excited state. The copolymers have spherical geometry as micelles, which were confirmed by TEM. We observed patterned arrangement of micelles and the arranged micelles appear to be pentagon in shape, creating space in between the arranged micelles; however, for PVCL50-PDMAEMA50, the arranged micelles do not form any particular shape. The thermal phase transition of PVCL-r-PDMAEMA in aqueous solution was studied by differential scanning calorimetry and thermal fluorescence spectroscopy. In order to design a biomimetic polymer for bio-specific applications and to understand novel concepts towards polymer-protein interactions, we studied the effect of insulin on lower critical solution temperature (LCST) of PVCL-r-PDMAEMA using multiple sophisticated techniques. The LCST is finely tuned by incorporation of two blocks with various block compositions and the value falls within the range of human body temperature, making PVCL50-PDMAEMA50 a highly compatible material for bio-medical and bio-material applications. Insulin forms a self-assembly with the monomers of PVCL-r-PDMAEMA, which leads to enhancing the micellar aggregates and the eventual decrease in the LCST of the diblock copolymer aqueous solution. The present study provides new insights into insulin-copolymer interactions and can be used for self-assembling nanocarriers and designing protein resistance surfaces.
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Affiliation(s)
- Krishan Kumar
- Department of Chemistry, University of Delhi, Delhi-110 007, India.
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Biomass-derived carbon helices induced phase transition in poly(N-ispropylacrylamide): A sustainable tailoring of coil-globule transition in thermoresponsive polymer. Colloids Surf B Biointerfaces 2020; 187:110637. [DOI: 10.1016/j.colsurfb.2019.110637] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/17/2019] [Accepted: 11/09/2019] [Indexed: 11/22/2022]
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Umapathi R, Kumar K, Venkatesu P, Deenadayalu N. Quantifying the influence of ionic liquid on the phase behaviour of a biomedical thermoresponsive polymer: A biophysical experimental approach. REACT FUNCT POLYM 2019. [DOI: 10.1016/j.reactfunctpolym.2019.104327] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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