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Here, we report a solid-phase approach to synthesize azobenzene and spiropyran derivatives. The divergent synthesis process requires no purification steps to obtain the desired product with a 28-55% yield, depending on the specific compound. For the spiropyran compounds, solid-phase resin cleavage is performed under mild conditions to minimize spiropyran ring opening. The solid-phase method enables the synthesis of a library of azobenzene and spiropyran derivatives without the need to develop purification strategies for each derivative.

We describe reversible force-induced metal–ligand coordination in spiropyran (SP) mechanophore linked PDMS elastomers. In the presence of lithium, calcium, or magnesium ions, SP is in equilibrium w...

In this work, we fabricated a stimulus-responsive biopolymeric material and demonstrated the reversible character of a hydrophilic/hydrophobic interface upon exposure to UV light. Importantly, this stimulus-responsive material exhibited excellent features in an oil/water separation system. Cellulose was functionalized on both sides of the surface with a dopamine polymer and further modified with an azobenzene-fluorosilane material. Azobenzene can alter the properties of a material via an isomerization effect (

In this work, we fabricated a thermosensitive hydrogel based on NIPAM that incorporated an oxygen-permeable hyaluronic acid (HA) polysaccharide unit. The interpenetrating network (IPN) of NIPAM-HA-MA hydrogel was fabricated by using an ultraviolet (UV) cross-linking process. Importantly, we explored the real behavior kinetics of the hydrogel via the mechanical properties of Young's modulus and the shear strain. The mechanical properties were reduced when the temperature was raised from 25 to 35 °C, and lower temperatures increased the rigidity of the IPN gel. This dynamic change occurred because of NIPAM's thermosensitive character. Further, IPN hydrogel exhibits good transparency with the incorporation of MA-HA and this stimuli-responsive hydrogel was biocompatible with a human dermal fibroblasts cell line (HDF). The cells adherence was densest when the temperature reached 37 °C and was reduced when the temperature was lowered to 25 °C. We envision using such hydrogels as mimics of cell-instructive biomaterials in tissue engineering applications.

The demand for lightweight, high-modulus, and temperature-resistant materials for aerospace and other high-temperature applications has contributed to the development of ceramic fibers that exhibit most of the favorable properties of monolithic ceramics. This review demonstrates preceramic-based polymer fiber spinning and fiber classifications. We discuss different types of fiber spinning and the advantages of each. Tuning the preceramic polymer chemical properties, molar mass, functional chemistry influences, and incorporation with fillers are thoroughly investigated. Further, we present the applications of preceramic-based polymer fibers in different fields including aerospace, biomedical, and sensor applications. This concise review summarizes recent developments in preceramic fiber chemistry and essential applications.

Appraisal of changes in plant functional behavior due to altitudinal gradients have proved its utility for munificent congregation of communities and their rejoinder to universal and restricted ecological drivers. The accessibility of an ample range of nanostructures and its ability to strappingly defy microorganisms make ZnO a superlative material for antimicrobial impending and biotechnology. The current research endeavor demonstrates the upshot of altitudinal variations in phytochemicals, & antimicrobial and antioxidant activities of Ag nanoparticles (AgNPs) and Ag doped ZnO (Ag-ZnO) nanostructures synthesized in the presence of the floral extract of C. officinalis. The aforementioned plant was collected from three diverse altitudes in Himachal Pradesh, (India). Silver (Ag), Zinc oxide (ZnO), and Ag-ZnO NPs were synthesized in the presence of the floral extract of C. officinalis collected from the Shimla (2104masl), Mandi (1235masl) and Kangra (733masl) hills in the Himalayas. Structural, morphological, and vital ocular properties of the same were inspected. Among Ag NPs, the ones from the Kangra floral extract revealed the maximum inhibition zone (20.83±1.20) against S. aureus, whereas ZnO demonstrated the maximum activity (23.65±1.59) against K. pneumonia . Results also indicated that lower ranges favor the increased potential of antimicrobial activity in floral extracts and synthesized AgNPs from among all the altitudinal ranges. Synergistic effects of Ag doped ZnO NPs and streptomycin showed amplified efficacies as signified by the enlarged zones of inhibition in comparison to their individual effects. The ensuing exertion provided a plausible scheme to develop nanostructures with enviable properties, possessing promising prospect in antimicrobial activity

Cell response to exogenous cues is the result of a complex integration of multiple biochemical/biophysical signals, which might occur simultaneously and might be characterized by specific spatial and temporal patterns. Among these signals, surface topography plays an important role in affecting cell functions and fate. However, the current understanding of the interplay between cells and topography relies on static environment. Here the intrinsic light-responsive properties of azopolymers and the versatility of laser-based confocal microscope technique is exploited, aiming to induce spatio-temporal dynamic topographic changes in situ during cell culture. Diverse patterns can be designed on cell-populated azopolymer films with high control on time, space, and on-off signal modification. The technique proposed in this study enables the development of synthetic platforms that finely control cell orientation and migration both in time and space. The results may pave the way to unravel complex processes involved in cell-topography interactions, thus allowing to define the spatio-temporal features that most effectively influence cell functions.

Photocatalytic hydrogen evolution from water splitting, using paper as an electron donor, was achieved upon the use of a hybrid photocatalyst of mesoporous TiO2 decorated with Ni nanoparticles. Through the involvement of a Ni cocatalyst, the separation and migration of photo-generated electrons in TiO2–Ni hybrids were significantly enhanced. The soluble paper in alkaline solution played the role of a sacrificial electron donor by reacting with hydroxyl radicals generated from hole oxidation with OH−. These findings provide an inexpensive route to drive aqueous proton reduction to hydrogen through waste biomass oxidation.

Photo-sensitive, smart switchable polymers are macromolecules that change its properties when irradiated with the light of the appropriate wavelength. Due to this uniqueness photo polymers has wide application. In this review we discuss the photopolymer chemistry and explain the changing the morphology of polymeric materials after exposing into light. Also we discussed photo-polymers applications in biomedical field.

The development of green nanomaterials from renewable resources is the utmost importance in a context of sustainable development. In this work, we describe the preparation of green nanomaterials of polymer, nanoparticles and hydrogel that arise from the natural extraction of myrcene and ocimene using air/water as a catalyst in one pot. Interestingly, we noticed the polymerization of myrcene in situ condition with attaining high molecular mass and low polydispersity index. The explanation of the polymerization kinetics that were investigated through nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). Importantly, we elucidated the preparation of green hydrogel by using water as a crosslinking agent. Further, we also described green nanoparticle formation by using emulsion method. The nanoparticles that obtained were 130 ±10 nm in terms of size and were found to be monodispersed. With these novel ‘green nanomaterials’, we project that they will be beneficial to multiple nanotechnological applications.

Spiropyran molecular switches, in conjunction with transition metal ions, are shown to operate as reversible polymer cross-linkers. Solutions containing a spiropyran-functionalized polymer and transition metal ions underwent reversible thermally triggered (light-triggered) transient network formation (disruption) driven by the association (dissociation) of metal-ligand cross-links. Heat triggers metal-ion-mediated cross-linking via thermal isomerization of spiropyran to its open, merocyanine form, and exposure to visible light triggers dissociation of polymer cross-links. Cross-linking is found to depend on both the valence of the ion as well as the molar ratio of spiropyran to metal salt. We envision this to be a starting point for the design of many types of reversible, stimuli-responsive polymers, utilizing the fact that spiropyrans have been shown to respond to a variety of stimuli including heat, light, pH, and mechanical force.

Pectin as polysaccharide polymer can be used in biomedical engineering and food industry due to its prominent properties such as biocompatibility and bio-degradability. Here, we first time reporting the preparation of nanowires and nanoparticles by water/oil emulsion method using methacrylated pectin (Ma-pectin). We have envisioned that these new materials can be considered as a new generation of biomaterials, which would pave the way for various biomedical engineering applications.

Oil/water separation has been of great interest worldwide because of the increasingly serious environmental pollution caused by the abundant discharge of industrial wastewater, oil spill accidents, and odors. Here, we describe simple and economical superhydrophobic hybrid membranes for effective oil/water separation. Eco-friendly, antifouling membranes were fabricated for oil/water separation, waste particle filtration, the blocking of thiol-based odor materials, etc., by using a cellulose membrane (CM) filter. The CM was modified from its original superhydrophilic nature into a superhydrophobic surface via a reversible addition-fragmentation chain transfer technique. The block copolymer poly{[3-(trimethoxysilyl)propyl acrylate]-block-myrcene} was synthesized using a "grafting-from" approach on the CM. The surface contact angle that we obtained was160°, and absorption tests of several organic contaminants (oils and solvents) exhibited superior levels of extractive activity and excellent reusability. These properties rendered this membrane a promising surface for oil/water separation. Interestingly, myrcene blocks thiol (through "-ene-" chemistry) contaminants, thereby bestowing a pleasant odor to polluted water by acting as an antifouling material. We exploited the structural properties of cellulose networks and simple chemical manipulations to fabricate an original material that proved to be effective in separating water from organic and nano/microparticulate contaminants. These characteristics allowed our material to effectively separate water from oily/particulate phases as well as embed antifouling materials for water purification, thus making it an appropriate absorber for chemical processes and environmental protection.

In this work, we synthesized end group functionalization of the cis-Norbornene-5-6-endo-dicarboxylic anhydride species via the ring-opening metathesis polymerization (ROMP) of oxanorbornene derivatives generated a chiseled poly(cis-Norbornene-5-6-endo-Dicarboxylic anhydride) acrylate macromonomer. Further, acrylate oxanorbornene based macromonomer further polymerized via reversible addition fragmentation chain transfer (RAFT) polymerization technique. Chain transfer is exhibited in the structure during the radical polymerizations so that free radical polymerization could also be used to comb structure copolymers with a PDI value below 1.2 with the help of acrylate oxanorbornene. Atomic force microscopy reveals the comb shape of branched polymer brushes structure. This method involves polymerizable end-group attachment to a macromonomer, and the backbone of the comb polymer is created in a second step of the polymerization. We believe that this kind of comb structured polymers can be considered for different biological applications.

Background: Neck pain is a common disorder prevailing among individuals of different populations. The myofascial pain syndrome is a disorder related to myofascial trigger points. It is defined as a hyperirritable locus in skeletal muscle and that is associated with a hypersensitive palpable nodule in a taut band of muscle. Manual therapy has got a profound role in treating and ischemic compression technique has been researched widely. Thus the study intends to analyse the effectiveness of Manual Therapy (Ischemic Compression) on functional outcome in neck pain. Methods: A single blinded randomized control study was conducted for subjects of sample size 30 who met the inclusion criteria and random allocation was made. The baseline parameters as like pain severity using VAS, pain pressure threshold using pressure Algometer, active cervical lateral flexion using 360 degree goniometer and disability using NDI were recorded. Study group received ischemic compression followed by myofascial stretches while the control group received ultrasonic therapy of 1.4watts/cm2. Both received Cryotherapy post session. After 2 weeks the baseline parameters were again recorded for t-test analysis. Result: There was no statistical significance between groups (p≥0.05). But active cervical lateral flexion showed improved mobility in study group and a high statistical significance within groups (p≤0.01) in relation to all parameters. Conclusion: Both ultrasonic therapy and Ischemic compression technique was found to show better improvement in pain pressure threshold and functional outcome in neck pain. Keywords: Myofascial trigger points, Trapezius muscle, Ischemic compression, Pressure Algometer, cervical lateral flexion and neck disability index

Understanding the response to illumination at a molecular level as well as characterising polymer brush dynamics are key features that guide the engineering of new light-stimuli responsive materials. Here, we report on the use of a confocal microscopy technique that was exploited to discern how a single molecular event such as the photoinduced isomerisation of azobenzene can affect an entire polymeric material at a macroscopic level leading to photodriven mass-migration. For this reason, a set of polymer brushes, containing azobenzene (Disperse Red 1, DR) on the side chains of poly(methacrylic acid), was synthesised and the influence of DR on the polymer brush dynamics was investigated for the first time by Fluorescence Correlation Spectroscopy (FCS). Briefly, two dynamics were observed, a short one coming from the isomerisation of DR and a long one related to the brush main chain. Interestingly, photoinduced polymer aggregation in the confocal volume was observed.

Fabrication of biodegradable polymer nanoparticles (NPs) is a fascinating research area because of their great potential in biomedical applications. In this work, apart from the well-reported di- or tri-block copolymer nanoassembly, homopolymers based on poly(caprolactone) were designed, synthesized and fabricated to obtain 200 nm size NPs, controlled by the duration of the ultraviolet (UV) cross-linking process. Furthermore, the encapsulated drug, doxorubicin, and the cross-linked NP system were produced via a UV cross-linking micro-emulsion process. Importantly, the drug-encapsulated NPs were taken up intracellularly and cytotoxicity studies were carried out in two different cell lines, HUVEC and SK-OV-3. The NP system reported here is a complimentary approach to existing therapeutic agents in biomedical engineering based on the straightforward utility of a single UV cross-linkable polymer with the ability to encapsulate and release drugs. It holds the promise of fine-tuning nano carriers for the targeted release of therapeutic moieties or growth factors, expanding the possibilities of tissue engineering.

Polysaccharide polymer has advantageous applications in bio-field, engineering and food industry because of remarkable properties such as biocompatibility and biodegradability. In this review, we describe the pectin polysaccharide nanomaterials and how the chemistry of pectin works in the development of nanoparticles and nanowires fabrication. We also discussed the recent advances of pectin-based nanomaterials including their synthesis strategies and applications. This pectin nanoscience review can be more useful to gain insight into the pectin nanochemistry for the nanosciences of engineering.