Thermo Response Research Articles

Thermoresponsive Bentonite for Water-Based Drilling Fluids.

As an important industrial material, bentonite has been widely applied in water-based drilling fluids to create mud cakes to protect boreholes. However, the common mud cake is porous, and it is difficult to reduce the filtration of a drilling fluid at high temperature. Therefore, this paper endowed bentonite with a thermo response via the insertion of N-isopropylacrylamide (NIPAM) monomers. The interaction between NIPAM monomers and bentonite was investigated via Fourier infrared spectroscopy (FTIR), isothermal adsorption, and X-ray diffraction (XRD) at various temperatures. The results demonstrate that chemical adsorption is involved in the adsorption process of NIPAM monomers on bentonite, and the adsorption of NIPAM monomers accords with the D–R model. With increasing temperature, more adsorption water was squeezed out of the composite when the temperature of the composite exceeded 70 °C. Based on the composite of NIPAM and bentonite, a mud cake was prepared using low-viscosity polyanionic cellulose (Lv-PAC) and initiator potassium peroxydisulfate (KPS). The change in the plugging of the mud cake was investigated via environmental scanning electron microscopy (ESEM), contact angle testing, filtration experiments, and linear expansion of the shale at various temperatures. In the plugging of the mud cake, a self-recovery behavior was observed with increasing temperature, and resistance was observed at 110 °C. The rheology of the drilling fluid was stable in the alterative temperature zone (70–110 °C). Based on the high resistance of the basic drilling fluid, a high-density drilling fluid (ρ = 2.0 g/cm3) was prepared with weighting materials with the objective of drilling high-temperature formations. By using a high-density drilling fluid, the hydration expansion of shale was reduced by half at 110 °C in comparison with common bentonite drilling fluid. In addition, the rheology of the high-density drilling fluid tended to be stable, and a self-recovery behavior was observed.

A circulating tumor cell specific RNA assay for assessment of androgen receptor signaling inhibitor sensitivity in metastatic castration-resistant prostate cancer.

5059 Background: Our objective is to develop a circulating tumor cell (CTC)-RNA assay for characterizing clinically relevant RNA signatures for the assessment of androgen receptor signaling inhibitors (ARSIs) sensitivity in metastatic castration-resistant prostate cancer (mCRPC) patients. Methods: We developed NanoVelcro CTC-RNA Assay by combining Thermoresponsive(TR)-NanoVelcro CTC purification system with NanoString nCounter platform for CTC purification and RNA analysis. Based on the well-validated, tissue-based Prostate Cancer Classification System (PCS), we selected the most aggressive and ARSI-resistant subtype- the PCS1, for CTC analysis. We applied a rigorous bioinformatic process to develop a CTC-PCS1 panel that is specific to PC CTCs. We validated NanoVelcro CTC-RNA Assay and CTC-PCS1 panel with PC cell lines to demonstrate sensitivity and specificity of the PCS1 Z score (the likelihood estimate of the PCS1 subtype) for identifying PCS1 subtype and ARSI resistance. We then selected 31 blood samples from 23 PC patients receiving ARSIs to test in our assay. The PCS1 Z score of each sample was computed and compared with ARSI treatment sensitivity. Results: We established a 16-gene CTC-PCS1 panel that consists of CTC-specific RNA signatures. The validation studies using PC cell lines showed that the assay can detect the RNA transcripts with high sensitivity and scalability in the range of 1-100 cells. We also showed that the genes in CTC-PCS1 panel is highly expressed in PC cells. We further demonstrated that the CTC-PCS1 panel is highly specific in identifying PCS1-like samples, and the high PCS1 Z score is associated with ARSI resistance. In patient bloods, ARSI-resistant samples (ARSI-R, n=14) had significantly higher PCS1 Z scores as compared with ARSI-sensitive samples (ARSI-S, n=17) (Rank-sum test, P=0.003). In 8 patients who were initially sensitive to ARSI (ARSI-S) and later developed resistance (ARSI-R), we found that the PCS1 Z score increased from the time of ARSI-S to the time of ARSI-R (Pairwise T-test, P=0.016). Conclusions: Using our new methodology, we developed a first-in-class CTC-RNA assay and demonstrated the feasibility of transforming clinically-relevant tissue-based RNA profiling into CTC tests. This approach allows for detecting RNA expression relevant to clinical drug resistance in a non-invasive fashion, which can facilitate patient-specific treatment selection and early detection of drug resistance- a goal in precision oncology.

A circulating tumor cell RNA assay for dynamic assessment of androgen receptor signaling inhibitors sensitivity in metastatic castration-resistant prostate cancer.

157 Background: Tissue-based gene signatures can predict clinical behavior in prostate cancer (PC). Our objective was to extend their application to circulating tumor cells (CTCs) and to show that changes in the signature were associated with changes in clinical behavior. Methods: Our approach combined the Thermoresponsive(TR)-NanoVelcro CTC purification system with the Nanostring nCounter system for cellular purification and transcriptomic analysis. The Prostate Cancer Classification System (PCS) panel was modified for use in CTCs. We selected 31 blood samples from 23 PC patients receiving androgen receptor signaling inhibitors (ARSI) and measured the PCS1 Z score (probability). These findings were compared with clinical outcome data (responsiveness/resistance). Results: A modified, 16-gene PCS1 signature was established and validated through a rigorous bioinformatics process. We performed analytical validation of our combined CTC-RNA system to ensure reproducibility and specificity. In patient bloods, ARSI-resistant samples (ARSI-R, n = 14) had significantly higher PCS1 Z scores as compared with ARSI-sensitive samples (ARSI-S, n = 17) (Rank-sum test, P = 0.003). The analyzed bloods contained samples from 8 patients who developed resistance to an ARSI allowing for dynamic measurement of gene expression. Our analysis found that the PCS1 Z score increased at the time that ARSI-resistance emerged (Pairwise T-test, P = 0.016). Conclusions: Using this new methodology, contemporary, clinically-relevant gene signatures such as PCS could be measured non-invasively in CTCs. These findings can be used to relate gene expression to clinical drug response. This approach also allowed for measurement of dynamic variations of gene expression in individual patients over time that correlated to ARSI sensitivity.

A Circulating Tumor Cell-RNA Assay for Assessment of Androgen Receptor Signaling Inhibitor Sensitivity in Metastatic Castration-Resistant Prostate Cancer.

Rationale: Our objective was to develop a circulating tumor cell (CTC)-RNA assay for characterizing clinically relevant RNA signatures for the assessment of androgen receptor signaling inhibitor (ARSI) sensitivity in metastatic castration-resistant prostate cancer (mCRPC) patients.Methods: We developed the NanoVelcro CTC-RNA assay by combining the Thermoresponsive (TR)-NanoVelcro CTC purification system with the NanoString nCounter platform for cellular purification and RNA analysis. Based on the well-validated, tissue-based Prostate Cancer Classification System (PCS), we focus on the most aggressive and ARSI-resistant PCS subtype, i.e., PCS1, for CTC analysis. We applied a rigorous bioinformatic process to develop the CTC-PCS1 panel that consists of prostate cancer (PCa) CTC-specific RNA signature with minimal expression in background white blood cells (WBCs). We validated the NanoVelcro CTC-RNA assay and the CTC-PCS1 panel with well-characterized PCa cell lines to demonstrate the sensitivity and dynamic range of the assay, as well as the specificity of the PCS1 Z score (the likelihood estimate of the PCS1 subtype) for identifying PCS1 subtype and ARSI resistance. We then selected 31 blood samples from 23 PCa patients receiving ARSIs to test in our assay. The PCS1 Z scores of each sample were computed and compared with ARSI treatment sensitivity.Results: The validation studies using PCa cell line samples showed that the NanoVelcro CTC-RNA assay can detect the RNA transcripts in the CTC-PCS1 panel with high sensitivity and linearity in the dynamic range of 5-100 cells. We also showed that the genes in CTC-PCS1 panel are highly expressed in PCa cell lines and lowly expressed in background WBCs. Using the artificial CTC samples simulating the blood sample conditions, we further demonstrated that the CTC-PCS1 panel is highly specific in identifying PCS1-like samples, and the high PCS1 Z score is associated with ARSI resistance samples. In patient bloods, ARSI-resistant samples (ARSI-R, n=14) had significantly higher PCS1 Z scores as compared with ARSI-sensitive samples (ARSI-S, n=17) (Rank-sum test, P=0.003). In the analysis of 8 patients who were initially sensitive to ARSI (ARSI-S) and later developed resistance (ARSI-R), we found that the PCS1 Z score increased from the time of ARSI-S to the time of ARSI-R (Pairwise T-test, P=0.016).Conclusions: Using our new methodology, we developed a first-in-class CTC-RNA assay and demonstrated the feasibility of transforming clinically-relevant tissue-based RNA profiling such as PCS into CTC tests. This approach allows for detecting RNA expression relevant to clinical drug resistance in a non-invasive fashion, which can facilitate patient-specific treatment selection and early detection of drug resistance, a goal in precision oncology.

Textured Organogel Films Showing Unusual Thermoresponsive Dewetting, Icephobic, and Optical Properties

AbstractTextured organogel films showing thermoresponsive (TR)‐syneretic and optical behaviors are fabricated based on soft lithography, using micro/nanostructured master moulds, of polydimethylsiloxane infused with polymethylphenylsiloxane (PMPS) as a lubricating oil. The critical syneretic temperature (CST) of the organogels can be arbitrarily tuned in the range of −15–50 °C by varying the volume of PMPS. Below the CST, the oil is spontaneously released from the inside of the gel matrices to the topmost surface, and vice versa, and it gradually returns back to the matrices above the CST. In the lubricated state, the textured TR‐organogel film surfaces exhibit excellent dynamic hydrophobicity and icephobicity, i.e., ice can be easily removed from the surface without any additional force. Simultaneously, optical properties derived from surface micro/nanotextures, such as diffraction and antireflection, respectively, are clearly observed above the CST and disappear below the CST, because the surface textures are buried by the released PMPS. These unusual TR‐surface functionalities are found to be repeatable/switchable for several tens of times.

5-Methyl Salicylic Acid-Induced Thermo Responsive Reversible Transition in Surface Active Ionic Liquid Assemblies: A Spectroscopic Approach.

This article describes the formation of stable unilamellar vesicles involving surface active ionic liquid (SAIL), 1-hexadecyl-3-methylimidazolium chloride (C16mimCl), and 5-methyl salicylic acid (5mS). Turbidity, dynamic light scattering (DLS), transmission electron microscopy (TEM), and viscosity measurements suggest that C16mimCl containing micellar aggregates are transformed to elongated micelle and finally into vesicular aggregates with the addition of 5mS. Besides, we have also investigated the photophysical aspects of a hydrophobic (coumarin 153, C153) and a hydrophilic molecule (rhodamine 6G (R6G) perchlorate) during 5mS-induced micelle to vesicle transition. The rotational motion of C153 becomes slower, whereas faster motion is observed for R6G during micelle to vesicle transition. Moreover, the fluorescence correlation spectroscopy (FCS) measurements suggest that the translational diffusion of hydrophobic probe becomes slower in C16mimCl-5mS aggregates in comparison to C16mimCl micelle. However, a reverse trend in translational diffusion motion of hydrophilic molecule has been observed in C16mimCl-5mS aggregates. Moreover, we have also found that the C16mimCl-5mS containing vesicles are transformed into micelles upon enhanced temperature, and it is further confirmed by turbidity, DLS measurements that this transition is a reversible one. Finally, temperature-induced rotational motion of C153 and R6G has been monitored in C16mimCl-5mS aggregates to get a complete scenario regarding the temperature-induced vesicle to micelle transition.

Synthesis of Thermo-Sensitive Hydrogels from Free Radical Copolymerization of NIPAAm with MBA Initiated by Atmospheric Plasma Treatment

Thermo-sensitive hydrogels from free radical copolymerization of NIPAAm and crosslinking monomer MBA (p(NIPAAm-co-MBA)) using in situ liquid atmospheric DBD plasma are successfully synthesized as revealed by FTIR and solid state 13C-NMR analysis, despite a rather short polymerization time of 10 min. The addition of MBA crosslinking monomer exerts a positive influence on the p(NIPAAm-co-MBA) copolymerization process, particularly at higher monomer concentrations and incident plasma power as suggested by GPC analysis. The swelling capacity of the p(NIPAAm-co-MBA) hydrogels declines significantly when the MBA concentration increased due to better crosslinking efficiency during the copolymerization process. The decrease in swelling capacity of p(NIPAAm-co-MBA) is also displayed by cryo-SEM analysis as smaller pore sizes and higher pore density of hydrogels were detected. The thermo responsiveness of p(NIPAAm-co-MBA) hydrogels is confirmed by DSC analysis with LCST values similar to the LCTS value of p(NIPAAm) around 32 °C.

Hydrophilic magnetic nanoclusters with thermo-responsive properties and their drug controlled release

Synthesis and drug controlled release properties of thermo-responsive magnetic nanoclusters grafted with poly(N-isopropylacrylamide) (poly(NIPAAm)) and poly(NIPAAm-co-poly(ethylene glycol) methyl ether methacrylate) (PEGMA) copolymers were described. These magnetic nanoclusters were synthesized via an in situ radical polymerization in the presence of acrylamide-grafted magnetic nanoparticles (MNPs). Poly(NIPAAm) provided thermo-responsive properties, while PEGMA played a role in good water dispersibility to the nanoclusters. The ratios of PEGMA to NIPAAm in the (co)polymerization in the presence of the MNPs were fine-tuned such that the nanoclusters with good water dispersibility, good magnetic sensitivity and thermo responsiveness were obtained. The size of the nanoclusters was in the range of 50–100nm in diameter with about 100–200 particles/cluster. The nanoclusters were well dispersible in water at room temperature and can be suddenly agglomerated when temperature was increased beyond the lower critical solution temperature (LCST) (32°C). The release behavior of an indomethacin model drug from the nanoclusters was also investigated. These novel magnetic nanoclusters with good dispersibility in water and reversible thermo-responsive properties might be good candidates for the targeting drug controlled release applications.

Fabrication of PVCL-co-PMMA nanofibers with tunable volume phase transition temperatures and maintainable shape for anti-cancer drug release

Thermo responsive PVCL-co-PMMA nanofibers for controlled release of anticancer drugs were fabricated. The thermo response temperatures of the nanofibers could be easily tuned, and the fibrous shapes could be maintained after heating–cooling cycles.

Design and Characterization of an Injectable Tendon Hydrogel: A Novel Scaffold for Guided Tissue Regeneration in the Musculoskeletal System

A biocompatible hydrogel consisting of extracellular matrix (ECM) from human tendons is described as a potential scaffold for guided tissue regeneration and tissue engineering purposes. Lyophilized decellularized tendons were milled and enzymatically digested to form an ECM solution. The ECM solution properties are assessed by proteome analysis with mass spectrometry, and the material's rheological properties are determined as a function of frequency, temperature, and time. In vivo application of the gel in a rat model is assessed for remodeling and host cell repopulation. Histology for macrophage invasion, fibroblast repopulation, and nanoscale properties of the gel is assessed. Gel interaction with multipotent adipoderived stem cells (ASCs) is also addressed in vitro to assess possible cytotoxicity and its ability to act as a delivery vehicle for cells. Proteome analysis of the ECM-solution and gel mass spectroscopy identified the most abundant 150 proteins, of which two isoforms of collagen I represented more than 55% of the sample. Rheology showed that storage (G') and loss (G″) of the ECM solution were stable at room temperature but displayed sigmoidal increases after ∼15 min at 37°C, matching macroscopic observations of its thermo responsiveness. G' and G″ of the gel at 1 rad/s were 213.1±19.9 and 27.1±2.4 Pa, respectively. Electron microscopy revealed fiber alignment and good structural porosity in the gel, as well as invasion of cells in vivo. Histology also showed early CD68(+) macrophage invasion throughout the gel, followed by increasing numbers of fibroblast cells. ASCs mixed with the gel in vitro proliferated, indicating good biocompatibility. This ECM solution can be delivered percutaneously into a zone of tendon injury. After injection, the thermoresponsive behavior of the ECM solution allows it to polymerize and form a porous gel at body temperature. A supportive nanostructure of collagen fibers is established that conforms to the three-dimensional space of the defect. This hydrogel holds the distinctive composition specific for tendon ECM, where tissue-specific cues facilitate host cell infiltration and remodeling. The results presented indicate that injectable ECM materials from tendon may offer a promising alternative in the treatment of tendinopathies and acute tendon injuries.

Interfacing a Tetraphenylethene Derivative and a Smart Hydrogel for Temperature-Dependent Photoluminescence with Sensitive Thermoresponse

We report, for the first time, the design and synthesis of thermoresponsive (TR) photoluminescent (PL) hydrogel nanoparticles, with a core consisting of poly[styrene-co-(N-isopropylacrylamide)] (PS-co-PNIPAM) and a PNIPAM-co-PAA shell. PAA represents polyacrylic acid which interacts with our emitting molecule 1,2-bis[4-(2-triethylammonioethoxy)phenyl]-1,2-diphenylethene dibromide (d-TPE). The electrostatic interaction between each water-soluble d-TPE molecule and two AA repeat units activates these d-TPE molecules to exhibit strong PL. Our d-TPE doped PS-co-PNIPAM/PNIPAM-co-PAA particles in water display remarkable TR PL: the emission intensity decreased in the course of heating from 2 to 80 °C and recovered during cooling from 80 to 2 °C. Such linear, reversible, and sensitive TR PL is achieved by the use of both PAA and PNIPAM as the shell polymeric chain and by careful optimization of the d-TPE to AA feed molar ratio. Thus, the emission of the d-TPE molecule is affected sensitively by temperature. In addition to such an exceptionally temperature-dependent PL, the presence of CrO4(2-) resulted in the decrease of the emission intensity, which was also temperature-dependent. The present study provides a unified conceptual methodology to engineer functional water-dispersible hydrogel nanoparticles that are stimuli-responsive with the potential to advance various PL-based applications.

Dynamical analysis of antibody aggregation in the CHO cell culture with Thermo Responsive Protein A (TRPA) column

Background Aggregation of therapeutic antibody is generally occurred in its manufacturing process, and should be suppressed and removed because its potential risk for unexpected immune response [1,2]. Protein A affinity chromatography is the first purification step in the monoclonal antibody manufacturing. Although the affinity purification is a powerful technique, high affinity between protein A and antibody requires acidic condition (below pH 3.0) to elute the captured antibody molecules. Exposure to acidic condition can induce the denaturation and aggregation of antibody molecules, demonstrating the necessity of novel strategy to reduce the antibody aggregation in the affinity purification process. Here we introduced an ovel affinity purification strategy, thermo responsive protein A (TRPA) resin. TRPA is an engineered protein A ligand which adopts folded structure under 10°C and unfolds at moderate temperature, above 25°C. TRPA resin can control capture and elution of antibody by changing column temperature, making it possible to elute antibody molecules without low pH condition. In this study, we applied the TRPA column to the purification of Ex3 humanized IgGlike single-chained bispecific diabody-Fc (Ex3-scDb-Fc) [3]. The bispecific diabody is the promising candidate for next-generation therapeutic antibody, whereas it shows aggregation tendency. Furthermore, we observed the time-dependent formation of antibody aggregation in the culture process of the recombinant Chinese hamster ovary (CHO) cell line with TRPA column. Materials and methods CHO Top-H cell line producing the Ex3-scDb-Fc [4] was cultivated in a 1L-glass bioreactor with working volume of 750mL serum-free medium. Viable cell densities and antibody concentrations in the medium was determined with Vi-Cell XR™ cell viability analyzer (Beckman Coulter) and by ELISA, respectively. The bispecific diabody was purified with conventional protein A (PA) column or thermo

Synthesis and characterization of polysulfone-g-poly(2-alkyl-2-oxazoline)s

Novel amphiphilic graft copolymers of polysulfone (PSU) possessing hydrophilic poly(2-oxazoline) (POx) side chains were synthesized via the ‘grafting from’ method. The cationic ring-opening polymerizations of 2-methyl-2-ozaxoline, 2-ethyl-2-ozaxoline, and 2-propyly-2-ozaxoline were initiated by chloromethylated polysulfone macroinitiator (with 15% benzylchloride content), synthesized by chloromethylation of PSU, in the presence of sodium iodide. The effects of reaction time and type of monomer on the yield, and degree of polymerization were investigated. The obtained polymers were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry analyses. Thin films of graft copolymers were investigated by atomic force microscopy and contact angle measurements. The observed morphologies of thin films were consistent with the amphiphilic nature of the graft copolymers. The films showed temperature dependent surface hydrophobicity due to thermo responsiveness of POx.

Magnetised Thermo Responsive Lipid Vehicles for Targeted and Controlled Lung Drug Delivery

Conditions such as lung cancer currently lack non-invasively targetable and controlled release topical inhalational therapies. Superparamagnetic iron-oxide nanoparticles (SPIONs) have shown promising results as a targetable therapy. We aimed to fabricate and test the in-vitro performance of particles with SPION and drug within a lipid matrix as a potentially targetable and thermo-sensitive inhalable drug-delivery system. Budesonide and SPIONs were incorporated into lipid particles using oil-in-water emulsification. Particles size, chemical composition, responsiveness to magnetic field, thermosensitiveness and inhalation performance in-vitro were investigated. Particles of average diameter 2-4 μm with budesonide and SPIONs inside the lipid matrix responded to a magnetic field with 100% extraction at a distance of 5 mm. Formulations were shown to have accelerated rate of drug release at hyperthermic temperatures (45°C)--controlled release. The produced inhalation dry powder presented promising inhalation performance, with an inhalable fine particle fraction of 30%. The lipid system presented thermo-sensitive characteristics, suitable for controlled delivery, the model drug and SPION loaded lipid system was magnetically active and movable using simple permanent magnets, and the system demonstrates promise as an effective drug vehicle in targeted and controlled inhalation therapy.