Synthesis and characterization of silica nanoparticles with well-defined thermoresponsive PNIPAM via a combination of RAFT and click chemistry

Silica hairy nanoparticles: a promising material for self-assembling processes

"Hairy" nanoparticles (HNPs), i.e. inorganic NPs functionalized with polymer chains, are promising building blocks for the synthesis of advanced nanocomposite (NC) materials having several technological applications. Recent evidence shows that HNPs self-organize in a variety of anisotropic structures, resulting in an improvement of the functional properties of the materials, in which are embedded. In this paper, we propose a three-step colloidal synthesis of spherical SiO₂-HNPs, with controlled particle morphology and surface chemistry. In detail, the SiO₂ core, synthesized by a modified Stöber method, was first functionalized with a short-chain amino-silane, which acts as an anchor, and then covered by maleated polybutadiene (PB), a rubbery polymer having low glass transition temperature, rarely considered until now. An extensive investigation by a multi-technique analysis demonstrates that the synthesis of SiO₂-HNPs is simple, scalable, and potentially applicable to different kind of NPs and polymers. Morphological analysis shows the overall distribution of SiO₂-HNPs with a certain degree of spatial organization, suggesting that the polymer coating induces a modification of NP-NP interactions. The role of the surface PB brushes in influencing the special arrangement of SiO₂-HNPs was observed also in cis-1,4-polybutadiene (cis-PB), since the resulting NC exhibited the particle packing in "string-like" superstructures. This confirms the tendency of SiO₂-HNPs to self-assemble and create alternative structures in polymer NCs, which may impart them peculiar functional properties.

Internal Microstructure Dictates Interactions of Polymer-grafted Nanoparticles in Solution

Understanding the effects of polymer brush architecture on particle interactions in solution is requisite to enable the development of functional materials based on self-assembled polymer-grafted nanoparticles (GNPs). Static and dynamic light scattering of polystyrene-grafted silica particle solutions in toluene reveals that the pair interaction potential, inferred from the second virial coefficient, A 2, is strongly affected by the grafting density, σ, and degree of polymerization, N, of tethered chains. In the limit of intermediate σ (∼0.3 to 0.6 nm-2) and high N, A 2 is positive and increases with N. This confirms the good solvent conditions and can be qualitatively rationalized on the basis of a pair interaction potential derived for grafted (brush) particles. In contrast, for high σ > 0.6 nm-2 and low N, A 2 displays an unexpected reversal to negative values, thus indicating poor solvent conditions. These findings are rationalized by means of a simple analysis based on a coarse-grained brush potential, which balances the attractive core-core interactions and the excluded volume interactions imparted by the polymer grafts. The results suggest that the steric crowding of polymer ligands in dense GNP systems may fundamentally alter the interactions between brush particles in solution and highlight the crucial role of architecture (internal microstructure) on the behavior of hybrid materials. The effect of grafting density also illustrates the opportunity to tailor the physical properties of hybrid materials by altering geometry (or architecture) rather than a variation of the chemical composition.

Puromycin-Modified Silica Microsphere-Based Nascent Proteomics Method for Rapid and Deep Nascent Proteome Profile

Nascent proteome is crucial in directly revealing how the expression of a gene is regulated on a translation level. In the nascent protein identification, puromycin capture is one of the pivotal methods, but it is still facing the challenge in the deep profiling of nascent proteomes due to the low abundance of most nascent proteins. Here, we describe the synthesis of puromycin-modified silica microspheres (PMSs) as the sorbent of dispersive solid-phase microextraction and the establishment of the PMS-based nascent proteomics (PMSNP) method for efficient capture and analysis of nascent proteins. The modification efficiency of puromycin groups on silica microspheres reached 91.8% through the click reaction. After the optimization and simplification of PMSNP, more than 3500 and 3900 nascent proteins were rapidly identified in HeLa cells and mouse brains within 13.5 h, respectively. The PMSNP method was successfully applied to explore changes in the translation process in a biological stress model, namely, the lipopolysaccharide-stimulated HeLa cells. Biological functional analyses revealed the unique characters of the nascent proteomes and exhibited the superiority of the PMSNP in the identification of low abundance and secreted nascent proteins, thus demonstrating the sensitivity and immediacy of the PMSNP method.

Amphiphilic mPEG-Modified Oligo-Phenylalanine Nanoparticles Chemoenzymatically Synthesized via Papain

Amphiphilic mPEG-modified peptide nanoparticles were developed from oligo-phenylalanine (OPhe) nanoparticles (NPs) synthesized via papain. Tyndall effects indicate that OPhe NPs are amphiphobic. Addition of protein perturbants, sodium dodecyl sulfate (SDS), and urea, in the dispersion solution of OPhe NPs can significantly reduce the R _h,m value of NPs, from approximately 749.2 nm to about 200 nm. Therefore, the hydrophobic interaction and hydrogen bonding play major roles in maintaining the aggregation of OPhe NPs. Using the "grafting to" method, the methoxypolyethylene-modified OPhe NPs (mPEG-g-OPhe NPs) were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), ¹H NMR, electrospray ionization mass spectrometry (ESI-MS), and dynamic light scattering (DLS). The attenuated total reflectance (ATR) spectrum of OPhe NPs and mPEG-g-OPhe NPs demonstrate that the secondary structures of these NPs are mainly β-type. mPEG-g-OPhe NPs can self-aggregate into spherical micelles both in water and cyclohexane. Increasing the chain length of the mPEG moiety, the critical micellar concentrations of mPEG-g-OPhe NPs increased in water but decreased in cyclohexane. The light stability, thermal stability, hydrolysis stability, and encapsulation stability of curcumin were significantly promoted by encapsulation in the micelles formed by mPEG-g-OPhe NPs. The protective effects regularly varied with the variations in the mPEG chain length of mPEG-g-OPhe NPs.

Photoconjugation of temperature- and pH-responsive polymer with silica nanoparticles for separation and enrichment of bacteria

A new photoconjugation approach was developed to prepare nanoparticle-supported boronic acid polymer for effective separation and enrichment of bacteria. The photo-activated polymer immobilization was demonstrated by coupling an azide-modified copolymer of N-isopropylacrylamide and glycidyl methacrylate to a perfluorophenyl azide-modified silica surface. The thermoresponsive polymer was synthesized using reversible addition fragmentation chain transfer polymerization followed by conversion of the pendant epoxides into azide groups. The perfluorophenyl azide-modified silica nanoparticles were synthesized by an amidation reaction between amino-functionalized silica and pentafluorobenzoyl chloride, and a subsequent treatment with sodium azide. Bacteria-capturing boronic acid was conjugated to the silica-supported polymer chains via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction. The particle size, morphology and organic content of the composite nanoparticles were characterized systematically. The capability of the nanocomposite to bind Gram-positive and Gram-negative bacteria was investigated. The nanocomposite exhibited high binding capacities for E. coli (13.4 × 10⁷ CFU/mg) and S. epidermidis (7.66 × 10⁷ CFU/mg) in phosphate buffered saline. The new photoconjugation strategy enables fast and straightforward grafting of functional polymers on surface, which opens many new opportunities for designing functional materials for bioseparation and biosensing.

Nanoparticle-Enabled Dual Modulation of Phagocytic Signals to Improve Macrophage-Mediated Cancer Immunotherapy

Activation of the phagocytosis of macrophages to tumor cells is an attractive strategy for cancer immunotherapy, but the effectiveness is limited by the fact that many tumor cells express an increased level of anti-phagocytic signals (e.g., CD47 molecules) on their surface. To promote phagocytosis of macrophages, a pro-phagocytic nanoparticle (SNPA_CALR&aCD47 ) that concurrently carries CD47 antibody (aCD47) and a pro-phagocytic molecule calreticulin (CALR) is constructed to simultaneously modulate the phagocytic signals of macrophages. SNPA_CALR&aCD47 can achieve targeted delivery to tumor cells by specifically binding to the cell-surface CD47 and block the CD47-SIRPα pathway to inhibit the "don't eat me" signal. Tumor cell-targeted delivery increases the exposure of recombinant CALR on the cell surface and stimulates an "eat me" signal. Simultaneous modulation of the two signals enhances the phagocytosis of 4T1 tumor cells by macrophages, which leads to significantly improved anti-tumor efficacy in vivo. The findings demonstrate that the concurrent blockade of anti-phagocytic signals and activation of pro-phagocytic signals can be effective in macrophage-mediated cancer immunotherapy.

Biofunctional Janus particles promote phagocytosis of tumor cells by macrophages

Herein, a versatile strategy for the construction of biofunctional Janus particles (JPs) through the combination of Pickering emulsion and copper-free click chemistry is developed for the study of particle-mediated cell–cell interactions. A variety of biomolecules including bovine serum albumin (BSA), ferritin, transferrin (Tf), and anti-signal regulatory protein alpha antibodies (aSIRPα), etc., can be incorporated into the Janus platform in a spatially defined manner. JPs consisting of Tf and aSIRPα (Tf–SPA1–aSIRPα JPs) demonstrate a significantly improved binding affinity to either macrophages or tumor cells compared to their uniformly modified counterparts. More importantly, Tf–SPA1–aSIRPα JPs mediate more efficient phagocytosis of tumor cells by macrophages as revealed by real-time high-content confocal microscopy. This study demonstrates the potential advantages of JPs in mediating cell–cell interactions and may contribute to the emerging cancer immunotherapy.

A versatile Janus particle platform modified with biological ligands can facilitate tumor cell phagocytosis by macrophages for promising cancer immunotherapy.

Synthesis of Poly(methyl methacrylate) Grafted Multiwalled Carbon Nanotubes via a Combination of RAFT and Alkyne-Azide Click Reaction

An efficient synthesis route was developed for the preparation of multiwalled carbon nanotube (MWCNT) nanohybrids using azide-terminated poly(methyl methacrylate) (PMMA) via a combination of reversible addition fragmentation chain transfer (RAFT) and the click reaction. A novel azido-functionalized chain transfer agent (DMP-N3) was prepared and subsequently employed to mediate the RAFT polymerizations of methyl methacrylate (MMA). The RAFT polymerizations exhibited first-order kinetics and a linear molecular weight dependence with the conversion. The kinetic results show that the grafting percentage of PMMA on the MWCNTs surface grows along with the increase of the reaction time. Even at 50 °C, the grafting rate of azide-terminated PMMA is comparatively fast in the course of the click reaction, with the alkyne groups adhered to MWCNTs in less than 24 h. The successful functionalization of PMMA onto MWCNT was proved by FTIR, while TGA was employed to calculate the grafting degree of PMMA chains (the highest GP = 21.9%). Compared with the pristine MWCNTs, a thicker diameter of the MWCNTs-g-PMMA was observed by TEM, which confirmed the grafted PMMA chain to the surface of nanotubes. Therefore, the MWCNTs-g-PMMA could be dispersed and stably suspended in water.

Radical Cation Initiated Surface Polymerization on Photothermal Rubber for Smart Antifouling Coatings

Biofouling on surfaces of various materials has attracted considerable attention in biomedical and marine industries. Surface grafting based on covalent surface-initiated polymerization offers a popular route to address this problem by providing diverse robust polymer coatings capable of preventing the biofouling in complex environments. However, the existing methods for synthesizing polymer coatings are complicated and rigorous, or require special catalysts, greatly limiting their practical applications. In this work, a radical-cation-based surface-initiated polymerization protocol to graft the surface of darkened trans-polyisoprene (TPI) rubber with a thermo-responsive smart polymer, poly(N-isopropylacrylamide) (PNIPAM), through a simple iodine doping process is reported. A series of characterizations were performed to provide adequate evidence to confirm the successful grafting. Combining the thermal sensitivity of PNIPAM with the photothermal conversion ability of the darkened rubber, efficient bacteria-killing and antifouling capabilities were successfully achieved as a result of temperature-controlled iodine release and switchable amphiphilicity of PNIPAM.

From proof-of-concept material to PEGylated and modularly targeted ultrasound-responsive mesoporous silica nanoparticles

In this work we present the synthesis, characterization and in vitro biological evaluation of PEGylated and actively-targeted ultrasound-responsive hybrid mesoporous silica nanoparticles. This work covers the development of the chemical strategies necessary to afford a modular nanocarrier starting from a proof-of-concept material presented in previous work. This functional ultrasound-responsive material can be adapted to different specific pathological conditions by carefully choosing the appropriate targeting moieties. The new ultrasound responsive material is able to target HeLa cells when conjugated with biotin or an RGD peptide. Ultrasound-responsive cytotoxicity towards cancer cells of doxorubicin-loaded nanoparticles is demonstrated in an in vitro cytotoxicity assay.

Packed hybrid silica nanoparticles as sorbents with thermo-switchable surface chemistry and pore size for fast extraction of environmental pollutants

Thermoresponsive poly(N-isopropylacrylamide)-grafted silica nanoparticles (SiNPs) have been synthesized and fully characterized by ATR-FTIR, TGA, HRTEM, BET and DLS analysis. Hybrid solid phase extraction (SPE) beds with tuneable pore size and switchable surface chemistry were prepared by packing the polymer-grafted nanoparticles inside SPE cartridges. The cartridges were tested by checking the thermo-regulated elution of model compounds, namely methylene blue, caffeine and amoxicillin. Extraction of the analytes and regeneration of the interaction sites on the sorbent surface was carried out entirely in water solution by changing the external temperature below and above the lower critical solution temperature (LCST) of the polymer. The results demonstrate that the elution of model compounds depends on the temperature-regulated size of the inter-particle voids and on the change of surface properties of the PNIPAM-grafted nanoparticles from hydrophilic to hydrophobic.

Thermoresponsive poly(N-isopropylacrylamide)-grafted silica nanoparticles were synthesized and used to prepare solid phase extraction sorbents with switchable pore size and surface chemistry for temperature-regulated extraction of water pollutants.

Preparation of novel magnetic molecular imprinted polymers nanospheres via reversible addition - fragmentation chain transfer polymerization for selective and efficient determination of tetrabromobisphenol A

A well-defined molecularly imprinted polymer nanospheres with excellent specific recognition ability was prepared on Fe₃O₄ nanoparticles via the combination of click chemistry and surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization and using Tetrabromobisphenol A as template. Concretely, Fe₃O₄ nanoparticles were prepared by solvothermal method and then modified by 4-vinylbenylchloride through distillation-precipitation, which makes azide groups easily introduced on the surface of magnetic nanoparticles to form the relatively large amount of benzyl chloride groups. With high efficiency, alkyne terminated RAFT chain transfer agent were then immobilized onto the surface of Fe₃O₄ by means of click chemistry, which is Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The highly uniform imprinted thin film was finally fabricated on the surface of RAFT agent modified Fe₃O₄ nanoparticles. The binding results demonstrated that as-prepared imprinted beads exhibited remarkable molecular imprinting effects to the template molecule, fast rebinding kinetics and an excellent selectivity to compounds with similar configuration.

Thermoresponsive Stability of Colloids in Butyl Acetate/Ethanol Binary Solvent Realized by Grafting Linear Acrylate Copolymers

We have developed a new class of thermoresponsive colloids that can exhibit a sharp reversible transition between dispersion and aggregation in binary BuAc/EtOH solvents based on the UCST (upper critical solution temperature)-type phase separation. This is realized by grafting linear PMMA-BA (random) copolymer onto the colloidal particles. We have selected TiO₂/PS hybrid spheres (HSs) as a model system to demonstrate our general design concept. By grafting the linear PMMA-BA copolymer onto the HS surface, with the molecular weight from 30 to 40 kDa, we found that the thermoresponsive transition between dispersion and aggregation is fast, sharp, and reversible. At high mass fractions of the HSs, we have even observed a sharp transition between dispersion and gelation (or phase separation). The transition temperature can be tuned by varying the binary solvent composition, BuAc/EtOH, and the molecular weight of the grafted linear copolymer in the range from 5 to 55 °C. One of the most important features of this work is that the thermoresponsive materials used in organic solvents are initially synthesized in water with widely applied conventional (instead of research-based) techniques, thus being well suited for industrial production. In addition, the proposed approach is rather general and applicable to realizing the thermoresponsive transition for various types of colloids and nanoparticles.

Temperature responsive fluorescent polymer nanoparticles (TRFNPs) for cellular imaging and controlled releasing of drug to living cells

Recent studies have demonstrated that drug delivery by using functional nanomaterials with imaging capability could afford plenty of insightful information for the better control of the delivery process. In this work, we developed temperature responsive fluorescent nanoparticles (TRFNPs) for drug delivery and cellular imaging. The TRFNP was fabricated by one-pot co-precipitation of thermal sensitive amphiphilic block copolymers polystyrene-b-poly(N-isopropyl acrylamide) (PS-b-PNIPAM) and fluorescent conjugated polymer poly [(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo(2,1',3)-thiadiazole)] (PFBT) in the presence of desired small guest molecules. The dynamic light scattering (DLS) measurements verified that this functional nanoparticle exhibited temperature dependent size variation, which could therefore regulate the releasing rate of loaded guest molecules (e.g. drugs) inside the polymer core. Besides, the TRFNPs displayed good photostability in terms of optical characterization. The cellular cytotoxicity characterization demonstrated that this nanoparticle exhibited good biocompatibility even under the mass concentration of 10μg/mL. By using Nile Red as a model molecule, the temperature-controlled releasing process from TRFNPs in solution as well as inside living cells was monitored directly according to the spectroscopic and microscopic characterizations. Furthermore, anti-cancer drug was successfully delivered into living cells via TRFNPs and released in a temperature dependent manner. As a consequence, owing the attractive merits as mentioned above, this nanostructure would find broad applications in nanomedicine in the future.

Nanotechnology-based combination therapy for overcoming multidrug-resistant cancer

Multidrug resistance (MDR) is a major obstacle to successful cancer treatment and is crucial to cancer metastasis and relapse. Combination therapy is an effective strategy for overcoming MDR. However, the different pharmacokinetic (PK) profiles of combined drugs often undermine the combination effect in vivo, especially when greatly different physicochemical properties (e.g., those of macromolecules and small drugs) combine. To address this issue, nanotechnology-based codelivery techniques have been actively explored. They possess great advantages for tumor targeting, controlled drug release, and identical drug PK profiles. Thus, a powerful tool for combination therapy is provided, and the translation from in vitro to in vivo is facilitated. In this review, we present a summary of various combination strategies for overcoming MDR and the nanotechnology-based combination therapy.

Mesoporous silica nanoparticles for stimuli-responsive controlled drug delivery: advances, challenges, and outlook

With the development of nanotechnology, the application of nanomaterials in the field of drug delivery has attracted much attention in the past decades. Mesoporous silica nanoparticles as promising drug nanocarriers have become a new area of interest in recent years due to their unique properties and capabilities to efficiently entrap cargo molecules. This review describes the latest advances on the application of mesoporous silica nanoparticles in drug delivery. In particular, we focus on the stimuli-responsive controlled release systems that are able to respond to intracellular environmental changes, such as pH, ATP, GSH, enzyme, glucose, and H2O2. Moreover, drug delivery induced by exogenous stimuli including temperature, light, magnetic field, ultrasound, and electricity is also summarized. These advanced technologies demonstrate current challenges, and provide a bright future for precision diagnosis and treatment.

A star-shaped amphiphilic block copolymer with dual responses: synthesis, crystallization, self-assembly, redox and LCST–UCST thermoresponsive transition

The micelles/aggregates that were self-assembled from a star-shaped copolymer presented redox-responsive behaviour and LCST–UCST thermoresponsive transition.

Recent advances in organic–inorganic well-defined hybrid polymers using controlled living radical polymerization techniques

Controlled living radical polymerizations, such as ATRP and RAFT polymerization, could be utilized for the preparation of well-defined organic–inorganic hybrid polymers based on POSS, PDMS, silica nanoparticles, graphene, CNTs and fullerene.

Advances in click chemistry for silica-based material construction

Click chemistry is undoubtedly the most powerful 1,3-dipolar cycloaddition reaction in organic synthesis.

Dual Stimuli-Responsive Vesicular Nanospheres Fabricated by Lipopolymer Hybrids for Tumor-Targeted Photodynamic Therapy

Smart delivery system of photosensitizer chlorin e6 (Ce6) has been developed for targeted photodynamic therapy (PDT). Simple self-assemblies of the mixtures comprising soybean lecithin derived phosphatidylcholine (PC), phosphatidylethanolamine-poly(L-histidine)40 (PE-p(His)40), and folic acid (FA) conjugated phosphatidylethanolamine-poly(N-isopropylacrylamide)40 (PE-p(NIPAM)40-FA) in different ratios yield smart nanospheres characterized by (i) stable and uniform particle size (∼100 nm), (ii) positive surface charge, (iii) high hydrophobic drug (Ce6) loading efficiency up to 45%, (iv) covalently linked targeting moiety, (v) low cytotoxicity, and (vi) smartness showing p(His) block oriented pH and p(NIPAM) oriented temperature responsiveness. The Ce6-encapsulated vesicular nanospheres (Ce6@VNS) were used to confirm the efficiency of cellular uptake, intracellular distribution, and phototoxicity against KB tumor cells compared to free Ce6 at different temperature and pH conditions. The Ce6@VNS system showed significant photodynamic therapeutic efficiency on KB cells than free Ce6. A receptor-mediated inhibition study proved the site-specific delivery of Ce6 in targeted tumor cells.

Polymer-Grafted Mesoporous Silica Nanoparticles as Ultrasound-Responsive Drug Carriers

A new ultrasound-responsive system based on mesoporous silica nanoparticles was developed for biomedical applications, grafting a copolymer on their surface that acts as gatekeeper of the pores. The nanoparticles can be loaded with a cargo at low temperature (4 °C), taking advantage of the open conformation that the polymer presents under these conditions. Then, at 37 °C the copolymer collapses closing the pore entrances and allowing the nanoparticles to carry the drugs at physiological temperature without premature release, which is of great importance when dealing with cytotoxic drugs in cancer treatments. Upon ultrasound irradiation, the sensitive polymer changes its hydrophobicity and, therefore, its conformation toward coil-like opening the gates and releasing the cargo. These hybrid nanoparticles have been shown to be noncytotoxic and can be internalized into LNCaP cells retaining their ultrasound-responsive capability in the cytoplasm of the cells. Moreover, doxorubicin-loaded hybrid MSNs were incubated with LNCaP cells to show their capacity to induce cell death only when the nanoparticles had been exposed to ultrasound. This work demonstrates that our hybrid-MSNs can be triggered by remote stimuli, which is of capital importance for future applications in drug delivery and cancer therapy.

Surface-initiated controlled radical polymerizations from silica nanoparticles, gold nanocrystals, and bionanoparticles

This review summarizes recent progress in surface-initiated controlled radical polymerizations from silica nanoparticles, gold nanocrystals, and bionanoparticles.

Folic acid-tethered poly(N-isopropylacrylamide)–phospholipid hybrid nanocarriers for targeted drug delivery

Folic acid-tethered poly(N-isopropylacrylamide)–phospholipid nanocarriers exhibit tumour targetability and temperature responsive Doxorubicin releasing behaviour under physiological conditions.

Structure and properties of polybenzimidazole/silica nanocomposite electrolyte membrane: influence of organic/inorganic interface

Although increased number of reports in recent years on proton exchange membrane (PEM) developed from nanocomposites of polybenzimidazole (PBI) with inorganic fillers brought hope to end the saga of contradiction between proton conductivity and variety of stabilities, such as mechanical, thermal,chemical, etc.; it still remains a prime challenge to develop a highly conducting PEM with superior aforementioned stabilities. In fact the very limited understanding of the interactions especially interfacial interaction between PBI and inorganic filler leads to confusion over the choice of inorganic filler type and their surface functionalities. Taking clue from our earlier study based on poly(4,4'-diphenylether-5,5'-bibenzimidazole) (OPBI)/silica nanocomposites, where silica nanoparticles modified with short chain amine showed interfacial interaction-dependent properties, in this work we explored the possibility of enhanced interfacial interaction and control over the interface by optimizing the chemistry of the silica surface. We functionalized the surface of silica nanoparticles with a longer aliphatic chain having multiple amine groups (named as long chain amine modified silica and abbreviated as LAMS). FTIR and (13)C solid-state NMR provided proof of hydrogen bonding interactions between the amine groups of modifier and those of OPBI. LAMS nanoparticles yielded a more distinguished self-assembly extending all over the OPBI matrix with increasing concentrations. The crystalline nature of these self-assembled clusters was probed by wide-angle X-ray diffraction (WAXD) studies and the morphological features were captured by transmission electron microscope (TEM). We demonstrated the changes in storage modulus and glass transition temperature (Tg) of the membranes, the fundamental parameters that are more sensitive to interfacial structure using temperature dependent dynamic mechanical analysis (DMA). All the nanocomposite membranes displayed enhanced mechanical, thermal and chemical stability than neat OPBI. The lower water uptake and swelling ratio and volume in both acid and water reflected the more hydrophobic characteristic of the nanocomposites. All the nanocomposite membranes showed phosphoric acid (PA) values to be higher than OPBI but the levels showed decreasing trend with increasing silica content; the reason attributed to the interparticle interaction. The self-assembled clusters of LAMS nanoparticles in the matrix created more sites for proton hopping as a result of which the proton conductivity of all the nanocomposites displayed an increasing trend.