Nanogels as pharmaceutical carriers: finite networks of infinite capabilities

Targeted delivery of cisplatin by сonnexin 43 vector nanogels to the focus of experimental glioma C6

The aim of this study was to create a nanocontainer conjugated with monoclonal antibodies to connexin 43 (Cx43) that is actively expressed at the periphery of C6 glioma and in the astroglia roll zone. Stable vector nanogels with high (up to 35%) cisplatin load were synthesized. The antitumor effects of Cx43-modified cisplatin-loaded nanogels, free cisplatin, and nonspecific drugs were carried out on C6 glioma model. Vector nanogels reduced systemic toxicity of cisplatin, effectively inhibited tumor growth, and significantly prolonged the lifespan of animals with experimental tumors.

Therapeutic potential of nanocarrier for overcoming to P-glycoprotein

Enhancement of targeted therapeutic effect in the body and achievement of high bioavailability are major concern for the researchers due to the complex physiology of human body. There are so many barriers that hinder the absorption and permeation of drugs from the body, thus influencing the bioavailability of therapeutics. P-glycoprotein (P-gp) is one of such barrier present on the apical membranes of various organs such as small intestine, brain, kidney and liver. This protein interacts with vast variety of therapeutics and efflux out them preventing their entrance to the desired site, thus modulating their pharmacokinetic properties. To address this, a concerned number of approaches have been used such as the use of chemo sensitizers along with the therapeutics and various novel techniques. In this review, we are going to discuss the basic introduction to this protein and overview of various strategies used earlier to tackle the problem of P-gp efflux as well as the role of nanocarriers in confronting this issue. Nanocarriers have played great role in the enhancement of the bioavailability of many antineoplastic agents as well as other P-gp substrates. Encapsulation of P-gp inhibitors in the nanocarrier system prevents toxicity and gives site-specific action.

Nanogel--an advanced drug delivery tool: Current and future

Nanogels are robust nanoparticles that could be used to deliver active drug compounds in controlled drug delivery applications. Nanogels drug delivery system is more effective and safer for both hydrophilic and hydrophobic drugs due to their chemical composition and formulations that are inappropriate for other formulations. Nanogels have enabled enlargement of functionalized nanoparticles, which act as a drug carriers that can be loaded with drugs and other active material to be released in a controlled manner at specific site. This review aims at providing general introduction on nanogels, recent synthesis methodology and their novel application in different fields.

Icam-1 targeted nanogels loaded with dexamethasone alleviate pulmonary inflammation

Lysozyme dextran nanogels (NG) have great potential in vitro as a drug delivery platform, combining simple chemistry with rapid uptake and cargo release in target cells with “stealth” properties and low toxicity. In this work, we study for the first time the potential of targeted NG as a drug delivery platform in vivo to alleviate acute pulmonary inflammation in animal model of LPS-induced lung injury. NG are targeted to the endothelium via conjugation with an antibody (Ab) directed to Intercellular Adhesion Molecule-1(ICAM-NG), whereas IgG conjugated NG (IgG-NG) are used for control formulations. The amount of Ab conjugated to the NG and distribution in the body after intravenous (IV) injection have been quantitatively analyzed using a tracer isotope-labeled [¹²⁵I]IgG. As a proof of concept, Ab-NG are loaded with dexamethasone, an anti-inflammatory therapeutic, and the drug uptake and release kinetics are measured by HPLC. In vivo studies in mice showed that: i) ICAM-NG accumulates in mouse lungs (∼120% ID/g vs ∼15% ID/g of IgG-NG); and, ii) DEX encapsulated in ICAM-NG, but not in IgG-NG practically blocks LPS-induced overexpression of pro-inflammatory cell adhesion molecules including ICAM-1 in the pulmonary inflammation.

Design of asymmetric particles containing a charged interior and a neutral surface charge: comparative study on in vivo circulation of polyelectrolyte microgels

Lowering the modulus of hydrogel particles could enable them to bypass in vivo physical barriers that would otherwise filter particles with similar size but higher modulus. Incorporation of electrolyte moieties into the polymer network of hydrogel particles to increase the swelling ratio is a straightforward and quite efficient way to decrease the modulus. In addition, charged groups in hydrogel particles can also help secure cargoes. However, the distribution of charged groups on the surface of a particle can accelerate the clearance of particles. Herein, we developed a method to synthesize highly swollen microgels of precise size with near-neutral surface charge while retaining interior charged groups. A strategy was employed to enable a particle to be highly cross-linked with very small mesh size, and subsequently PEGylated to quench the exterior amines only without affecting the internal amines. Acidic degradation of the cross-linker allows for swelling of the particles to microgels with a desired size and deformability. The microgels fabricated demonstrated extended circulation in vivo compared to their counterparts with a charged surface, and could potentially be utilized in in vivo applications including as oxygen carriers or nucleic acid scavengers.

Highly water-soluble, porous, and biocompatible boron nitrides for anticancer drug delivery

Developing materials for "Nano-vehicles" with clinically approved drugs encapsulated is envisaged to enhance drug therapeutic effects and reduce the adverse effects. However, design and preparation of the biomaterials that are porous, nontoxic, soluble, and stable in physiological solutions and could be easily functionalized for effective drug deliveries are still challenging. Here, we report an original and simple thermal substitution method to fabricate perfectly water-soluble and porous boron nitride (BN) materials featuring unprecedentedly high hydroxylation degrees. These hydroxylated BNs are biocompatible and can effectively load anticancer drugs (e.g., doxorubicin, DOX) up to contents three times exceeding their own weight. The same or even fewer drugs that are loaded on such BN carriers exhibit much higher potency for reducing the viability of LNCaP cancer cells than free drugs.

Sequential optimization of methotrexate encapsulation in micellar nano-networks of polyethyleneimine ionomer containing redox-sensitive cross-links

A functional polycation nanonetwork was developed for delivery of water soluble chemotherapeutic agents. The complexes of polyethyleneimine grafted methoxy polyethylene glycol (PEI-g-mPEG) and Zn(2+) were utilized as the micellar template for cross-linking with dithiodipropionic acid, followed by an acidic pH dialysis to remove the metal ion from the micellar template. The synthesis method was optimized according to pH, the molar ratio of Zn(2+), and the cross-link ratio. The atomic force microscopy showed soft, discrete, and uniform nano-networks. They were sensitive to the simulated reductive environment as determined by Ellman's assay. They showed few positive ζ potential and an average hydrodynamic diameter of 162±10 nm, which decreased to 49±11 nm upon dehydration. The ionic character of the nano-networks allowed the achievement of a higher-loading capacity of methotrexate (MTX), approximately 57% weight per weight, depending on the cross-link and the drug feed ratios. The nano-networks actively loaded with MTX presented some suitable properties, such as the hydrodynamic size of 117±16 nm, polydispersity index of 0.22, and a prolonged swelling-controlled release profile over 24 hours that boosted following reductive activation of the nanonetwork biodegradation. Unlike the PEI ionomer, the nano-networks provided an acceptable cytotoxicity profile. The drug-loaded nano-networks exhibited more specific cytotoxicity against human hepatocellular carcinoma cells if compared to free MTX at concentrations above 1 μM. The enhanced antitumor activity in vitro might be attributed to endocytic entry of MTX-loaded nano-networks that was found in the epifluorescence microscopy experiment for the fluorophore-labeled nano-networks.

Nanotechnology-applied curcumin for different diseases therapy

Curcumin is a lipophilic molecule with an active ingredient in the herbal remedy and dietary spice turmeric. It is used by different folks for treatment of many diseases. Recent studies have discussed poor bioavailability of curcumin because of poor absorption, rapid metabolism, and rapid systemic elimination. Nanotechnology is an emerging field that is potentially changing the way we can treat diseases through drug delivery with curcumin. The recent investigations established several approaches to improve the bioavailability, to increase the plasma concentration, and to enhance the cellular permeability processes of curcumin. Several types of nanoparticles have been found to be suitable for the encapsulation or loading of curcumin to improve its therapeutic effects in different diseases. Nanoparticles such as liposomes, polymeric nanoparticles, micelles, nanogels, niosomes, cyclodextrins, dendrimers, silvers, and solid lipids are emerging as one of the useful alternatives that have been shown to deliver therapeutic concentrations of curcumin. This review shows that curcumin's therapeutic effects may increase to some extent in the presence of nanotechnology. The presented board of evidence focuses on the valuable special effects of curcumin on different diseases and candidates it for future clinical studies in the realm of these diseases.

Facile route to versatile nanoplatforms for drug delivery by one-pot self-assembly

There is still unmet demand for developing powerful approaches to produce polymeric nanoplatforms with versatile functions and broad applications, which are essential for the successful bench-to-bedside translation of polymeric nanotherapeutics developed in the laboratory. We have discovered a facile, convenient, cost-effective and easily scalable one-pot strategy to assemble various lipophilic therapeutics bearing carboxyl groups into nanomedicines, through which highly effective cargo loading and nanoparticle formation can be achieved simultaneously. Besides dramatically improving water solubility, the assembled nanopharmaceuticals showed significantly higher bioavailability and much better therapeutic activity. These one-pot assemblies may also serve as nanocontainers to effectively accommodate other highly hydrophobic drugs such as paclitaxel (PTX). PTX nanomedicines thus formulated display strikingly enhanced in vitro antitumor activity and can reverse the multidrug resistance of tumor cells to PTX therapy. The special surface chemistry offers these assembled entities the additional capability of efficiently packaging and efficaciously transfecting plasmid DNA, with a transfection efficiency markedly higher than that of commonly used positive controls. Consequently, this one-pot assembly approach provides a facile route to multifunctional nanoplatforms for simultaneous delivery of multiple therapeutics with improved therapeutic significance.

Design and processing of nanogels as delivery systems for peptides and proteins

Nanogels, cross-linked networks of >1 μm in size, are attractive drug-delivery systems, as they not only possess the potential advantages of nanoscale formulations, but also the attractive abilities of a hydrogel; high hydrophilicity, high loading capacity and the potential for biocompatibility and controlled release. The focus of this review is to provide an overview of the recent developments within the nanogel field, and how the chemical design of the nanogel polymer has been found to influence the properties of the nanogel system. Novel nanogel systems are discussed with respect to their type of cross-linkage and their suitability as therapeutic delivery systems, as well as their ability to stabilize the protein/peptide drug.

Ligand exchange on gold nanoparticles for drug delivery and enhanced therapeutic index evaluated in acute myeloid leukemia models

Cancer chemotherapy is typically toxic. This problem could be addressed by using differences between cancer and normal cells for controlled delivery of drugs to cancer cells. One such difference is the ubiquitously elevated glutathione expression in cancer cells. We report a simple and versatile synthesis of water-soluble gold nanoparticles passivated with amine-containing molecules, which allow for controlled drug release via ligand exchange with bio-available glutathione. Taking methotrexate-passivated gold nanoparticles (Au:MTX) as an example, drug delivery and controlled release via glutathione-mediated ligand exchange was evaluated. Furthermore, the possibility of using Au:MTX to improve therapeutic index in acute myeloid leukemia (AML) models was examined in vitro and in vivo. Au:MTX exhibited cancer selectivity in vitro. Au:MTX had an elevated potency toward an AML cell line THP-1 in a dosage range of 1–5 nM, and therefore an enhanced delivery of drug, whereas normal hematopoietic stem/progenitor cell (HSPC) growth was minimally affected by Au:MTX and MTX treatments within the same range of dosage. In vivo efficacy and safety of Au:MTX was evaluated in a murine xenotransplant model of primary human AML. Au:MTX treatment, compared to control groups including MTX-only and Au nanoparticle-only treatments, produced better leukemia suppression without added toxicity, indicating an enhanced therapeutic index.

Ratiometric MRI sensors based on core-shell nanoparticles for quantitative pH imaging

Ratiometric MRI sensors consist of paramagnetic cores and pH-sensitive polymer shells. The core-shell nanostructure enables the coexistence of two incompatible NMR relaxation properties in one particle. The sensors show pH sensitivity in transverse relaxivity (r2 ), but not in longitudinal relaxivity (r1 ). Quantitative pH imaging is achieved by measuring the r2 /r1 value with a clinical 3 T MRI scanner.

Bioresponsive nanohydrogels based on HEAA and NIPA for poorly soluble drugs delivery

Environmentally sensitive hydrogels have gained considerable attention in recent years as one of the most promising drug delivery systems. In the present study, two new formulations of pH and temperature stimuli-responsive nanogels (NGs) based on poly-N-isopropylacrylamide (NIPA), N-hydroxyethyl acrylamide (HEAA) and tert-butyl 2-acrylamidoethyl carbamate (2AAECM) were synthesized and evaluated for passive targeting of paclitaxel (PTX). Nanogels were prepared by microemulsion polymerization method using N-methylenebis(acrylamide) (NMBA) as crosslinking agent. TEM images and DLS results showed nanosized spherical hydrogels. FTIR spectra confirmed the synthesis of nanogels by radical polymerization among vinyl groups of monomers. The PTX loading capacity, encapsulation efficiency and in vitro release were analyzed by HPLC. The cumulative release profile of the PTX-loaded nanohydrogels within 144h showed a faster drug release at acid pH (pH 5), similar to those observed at lysosome compartment, whereas a fewer PTX amount was released from NGs at pH similar to plasma levels. Cellular uptake assays revealed rapid penetration and intracellular accumulation of those nanogels in MCF7, HeLa and T47D cells after 48h incubation. MTT assays showed cell viability dependence on concentration and time incubation. Finally, the PTX effect on cell viability showed a G2/M cell arrest after using PTX-loaded NGs and pure PTX.

Naltrexone: a review of existing sustained drug delivery systems and emerging nano-based systems

Narcotic antagonists such as naltrexone (NTX) have shown some efficiency in the treatment of both opiate addiction and alcohol dependence. A few review articles have focused on clinical findings and pharmacogenetics of NTX, advantages and limitations of sustained release systems as well as pharmacological studies of NTX depot formulations for the treatment of alcohol and opioid dependency. To date, three NTX implant systems have been developed and tested in humans. In this review, we summarize the latest clinical data on commercially available injectable and implantable NTX-sustained release systems and discuss their safety and tolerability aspects. Emphasis is also laid on recent developments in the area of nanodrug delivery such as NTX-loaded micelles and nanogels as well as related research avenues. Due to their ability to increase the therapeutic index and to improve the selectivity of drugs (targeted delivery), nanodrug delivery systems are considered as promising sustainable drug carriers for NTX in addressing opiate and alcohol dependence.

Drug-induced morphology switch in drug delivery systems based on poly(2-oxazoline)s

Defined aggregates of polymers such as polymeric micelles are of great importance in the development of pharmaceutical formulations. The amount of drug that can be formulated by a drug delivery system is an important issue, and most drug delivery systems suffer from their relatively low drug-loading capacity. However, as the loading capacities increase, i.e., promoted by good drug-polymer interactions, the drug may affect the morphology and stability of the micellar system. We investigated this effect in a prominent system with very high capacity for hydrophobic drugs and found extraordinary stability as well as a profound morphology change upon incorporation of paclitaxel into micelles of amphiphilic ABA poly(2-oxazoline) triblock copolymers. The hydrophilic blocks A comprised poly(2-methyl-2-oxazoline), while the middle blocks B were either just barely hydrophobic poly(2-n-butyl-2-oxazoline) or highly hydrophobic poly(2-n-nonyl-2-oxazoline). The aggregation behavior of both polymers and their formulations with varying paclitaxel contents were investigated by means of dynamic light scattering, atomic force microscopy, (cryogenic) transmission electron microscopy, and small-angle neutron scattering. While without drug, wormlike micelles were present, after incorporation of small amounts of drugs only spherical morphologies remained. Furthermore, the much more hydrophobic poly(2-n-nonyl-2-oxazoline)-containing triblock copolymer exhibited only half the capacity for paclitaxel than the poly(2-n-butyl-2-oxazoline)-containing copolymer along with a lower stability. In the latter, contents of paclitaxel of 8 wt % or higher resulted in a raspberry-like micellar core.

Synthesis, characterization, and catalytic properties of cationic hydrogels containing copper(II) and cobalt(II) ions

Here, we report the synthesis and characterization of a hydrogel based on ethylene glycol diglycidyl ether (EGDE) and 1,8-diamino-3,6-dioxaoctane (DA). Chemically stable Co(II) and Cu(II) coordination complexes were prepared with this nonsoluble polyelectrolyte, poly(EGDE-DA), and studied by ss-NMR, FT-IR, thermogravimetry, and microscopy. Mesopores were found in all the samples, the thermal stability of the polymer matrix was highly affected by the presence of metal ions, and the (13)C CP-MAS spectrum for the Cu(II)-complex evidenced a significant increase in the reticulation degree by Cu(II) ions. The catalytic activity of these materials on H2O2 activation was studied by electron spin resonance (ESR). The Co(II)-poly(EGDE-DA)/H2O2 heterogeneous system produced O2, an anion superoxide (O2(•)¯), and a hydroxyl radical (OH(•)), which diffused into the solution at the time that a decrease in pH was detected. In the same way, the Cu(II)-poly(EGDE-DA)/H2O2 heterogeneous system produced O2 and OH(•). H2O2 activation by the poly(EGDE-DA) complexes with Co(II) and Cu(II) were applied on the decolorization of solutions of the azo-dye methyl orange (MO). In the presence of 63 mM H2O2, 87% of MO was removed in 10 min with Cu(II)-poly(EGDE-DA) and in 110 min with Co(II)-poly(EGDE-DA). In addition, the pharmaceutical product epinephrine was partially oxidized to adrenochrome by the O2(•)¯ released from the Co(II)-poly(EGDE-DA)/H2O2 heterogeneous system.

Nanogels with high active β-cyclodextrin content as physical coating system with sustained release properties

We present the application of nanogels with high functional β-cyclodextrin (β-CD) content as new and versatile method for the modification and protection of textiles. The complexation potential of covalently embedded β-CD in nanogels is demonstrated for the common insecticide permethrin in aqueous environment. It is shown that permethrin containing β-CD nanogels can be applied easily, homogeneously and safely on keratin fibers like wool fabrics and human hairs. The permethrin concentration on fibers is directly controlled by the permethrin content in nanogels. We tested the permanence of permethrin on treated fibers with regard to washing and UV fastness. Our results show that permethrin complexed in nanogels is removed from the textile during washing, but that the complexation of permethrin by β-CD domains in the nanogels protects the active ingredient from UV degradation. Bioassay tests against the larvae of Tineola bisselliella and Anthrenocerus australis show that the activity of the ingredients does not decrease after complexation in β-CD gels and it results in protection of the wool fibers against degradation by the insect larvae.

THE APPLICATION OF NANOMATERIALS IN DIAGNOSIS AND TREATMENT FOR MALIGNANT PRIMARY BRAIN TUMORS

Malignant primary brain tumors have a very high morbidity and mortality. Even though enormous advances have been made in primary brain tumor management, in the case of malignant primary brain tumors, current diagnostic strategies cannot identify exact infiltrating margins, surgery alone cannot achieve total mass resection, and adjuvant therapies cannot improve survivals. Therefore, there is an urgent need to explore novel strategies to diagnose and treat such infiltrating brain tumors. Nanomaterials, particularly zero-dimensional and one-dimensional platforms, can carry various compounds such as contrast agents, anticancer drugs and genes into brain tumor cells specifically. Thus, contrast agent-based nanomaterials can selectively present infiltrating tumor outlines, while anticancer agent-based nanomaterials can specifically kill malignant tumor cells. In addition, dual-targeting nanomaterials, multifunctional nanocarriers, theranostic nanovehicles as well as convection-enhanced delivery technology hold promise to increase drug accumulation in tumor tissues, which could largely improve anticancer efficacy. In this review, we will mainly focus on the application of nanomaterials in preoperative diagnosis, intraoperative diagnosis and adjuvant treatment for malignant primary brain tumors.

Dendrimer-assisted formation of fluorescent nanogels for drug delivery and intracellular imaging

Although, in general, nanogels present a good biocompatibility and are able to mimic biological tissues, their unstability and uncontrollable release properties still limit their biomedical applications. In this study, a simple approach was used to develop dual-cross-linked dendrimer/alginate nanogels (AG/G5), using CaCl2 as cross-linker and amine-terminated generation 5 dendrimer (G5) as a cocrosslinker, through an emulsion method. Via their strong electrostatic interactions with anionic AG, together with cross-linker Ca(2+), G5 dendrimers can be used to mediate the formation of more compact structural nanogels with smaller size (433 ± 17 nm) than that (873 ± 116 nm) of the Ca(2+)-cross-linked AG nanogels in the absence of G5. Under physiological (pH 7.4) and acidic (pH 5.5) conditions, the sizes of Ca(2+)-cross-linked AG nanogels gradually decrease probably because of their degradation, while dual-cross-linked AG/G5 nanogels maintain a relatively more stable structure. Furthermore, the AG/G5 nanogels effectively encapsulate the anticancer drug doxorubicin (Dox) with a loading capacity 3 times higher than that of AG nanogels. The AG/G5 nanogels were able to release Dox in a sustained way, avoiding the burst release observed for AG nanogels. In vitro studies show that the AG/G5-Dox NGs were effectively taken up by CAL-72 cells (a human osteosarcoma cell line) and maintain the anticancer cytotoxicity levels of free Dox. Interestingly, G5 labeled with a fluorescent marker can be integrated into the nanogels and be used to track the nanogels inside cells by fluorescence microscopy. These findings demonstrate that AG/G5 nanogels may serve as a general platform for therapeutic delivery and/or cell imaging.

Cellular uptake and intracellular trafficking of oligonucleotides: implications for oligonucleotide pharmacology

One of the major constraints on the therapeutic use of oligonucleotides is inefficient delivery to their sites of action in the cytosol or nucleus. Recently it has become evident that the pathways of cellular uptake and intracellular trafficking of oligonucleotides can strongly influence their pharmacological actions. Here we provide background information on the basic processes of endocytosis and trafficking and then review recent literature on targeted delivery and subcellular trafficking of oligonucleotides in that context. A variety of approaches including molecular scale ligand-oligonucleotide conjugates, ligand-targeted nanocarriers, and the use of small molecules to enhance oligonucleotide effects are discussed.

Doxorubicin-loaded poly(lactic-co-glycolic acid) hollow microcapsules for targeted drug delivery to cancer cells

Poly(lactic-co-glycolic acid) hollow microcapsules loaded with doxorubicin can be assembled with folate-functionalized polyethyleneimine for targeted drug delivery to cancer cells.

Fabrication of thermoresponsive nanogels by thermo-nanoprecipitation and in situ encapsulation of bioactives

Thermo-nanoprecipitation is presented as a versatile, surfactant-free, and mild synthetic method for the preparation of thermoresponsive nanogels and in situ encapsulation of bioactives.

A hydrazone crosslinked zwitterionic polypeptide nanogel as a platform for controlled drug delivery

A pH-responsive polypeptide nanogel was prepared via hydrazone self-crosslinking under mild conditions.

pH- and electro-response characteristics of bacterial cellulose nanofiber/sodium alginate hybrid hydrogels for dual controlled drug delivery

An ionic crosslinking nanocellulose/sodium alginate (BC/SA) hybrid hydrogel was prepared as a dual-stimuli responsive release system. The drug release rate of BC/SA hybrid hydrogels in vitro not only depend on pH value but also depend on the presence of electric stimulus.

Tuning Surface Microstructure and Gradient Property of Polymer by Photopolymerizable Polysiloxane-modified Nanogels

This paper reports a series of photopolymerizable polysiloxane-modified nanogels for regulating surface microstructure and gradient property of polymers, which were synthesized by solution polymerization under different feed ratios of a methacrylate-modified polysiloxane, urethane dimethacrylate (UDMA) and isobornyl methacrylate (IBMA) in the presence of a thiol chain transfer agent. The nanogel structure and composition were characterized by proton nuclear magnetic resonance (1H-NMR), Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscope (TEM), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The dispersion of these nanogels in triethylene glycol dimethacrylate (TEGDMA) can reduce the onset and magnitude of shrinkage stress during polymerization without compromise to mechanical properties of the resulting polymers. Most importantly, as demonstrated by elemental analysis and X-ray photoelectron spectroscopy (XPS), the nanogels exhibit good self-floating ability in the monomer/polymer matrix and the increase of polysiloxane content in the nanogel can enhance the self-floating capability due to the lower surface tension and energy associated with the polysiloxane component. As a result, the polysiloxane-modified nanogels can spontaneously form a concentration gradient that can be locked in upon photopolymerization leading to a well-controlled heterogeneous polymer that presents a gradient change in thermal stability. With the increase of polysiloxane content, the thermal stability of the polymer was improved significantly. Furthermore, the enrichment of the nanogel on the surface resulting from the good self-floating ability can reduce the dispersion surface energy of gradient polymer film and generate a more hydrophobic surface with altered surface microstructure. These photopolymerizable polysiloxane-modified nanogels are demonstrated to have potential broad application in the preparation of gradient polymer with controlled surface properties.