Inverse Miniemulsion Research Articles

Tunable, reagent‐loaded polyurethane nanocapsules cleavable by NIR light

AbstractDual response polyurethane nanocapsules consisting of a hydrophilic core are synthesized via interfacial polyaddition of the diisocyanate monomers and different diols (VA‐060 and glycols) in inverse miniemulsion process. The presence of the water‐soluble NIR dye in the core and azo‐bonds in the polymer shell allows the selective release of encapsulated material triggered by temperature or NIR light. The capsules are characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The capsule degradation under external stimuli, like temperature and NIR light, is confirmed microscopically by TEM. Macroscopic evidence of the capsule cleavage was achieved by the incorporation of the chemical into the capsule core, and subsequent treatment of the capsules with NIR laser in the presence of the suitable reagent outside the capsules. A color‐forming chemical reaction occurred after the shell opening. The reactions were easily detected by visual observation of a color change and by UV–Vis spectroscopy.

Salt-responsive polyamide thin-film nanocomposite membrane based on zwitterionic polymeric nanoparticles for high-efficient dye desalination

To simultaneously improve the water permeability, selectivity, and antifouling properties of polyamide nanofiltration (NF) membranes in textile wastewater treatment, we fabricated a salt-responsive thin-film nanocomposite (TFN) membrane with the incorporation of zwitterionic polymeric nanoparticles (ZNPs) into polyamide selective layer. Herein, the ZNPs were synthesized via an inverse miniemulsion polymerization with zwitterionic monomer, amino monomer, and cross-linker reagent. The salt-responsive property of ZNPs rendered their resultant membranes TFN-ZNPs with adjustable microstructure and separation performance via varying the sodium chloride (NaCl) concentration in water. The water permeance of TFN-ZNPs was enhanced to be 1.7 times that of its pure water permeance with the 10 g L−1 NaCl solution, and the salt-responsive behavior was reversible. Moreover, this salt-responsive property endowed the membrane with outstanding separation performance for the salt/dye or dye/dye mixtures. The selectivity of TFN-ZNPs to NaCl/congo red and methyl orange/neutral blue was enhanced to ∼104 and ∼127, respectively. The TFN-ZNPs with salt-responsive property also exhibited an improved antifouling performance, i.e., the flux recovery ratio was enhanced from 85.6 % to 96.5 % by washing with NaCl solution instead of deionized water. Thus, this work provided a paradigm shift in the fabrication of salt-responsive TFN membranes for the highly efficient separation of organic molecules and inorganic salts and wastewater treatment.

Fabrication and Release Mechanism Study of a Nanocapsule Breaker for Controlling Degradation Rate of Insoluble Residue in Slickwater at Moderate-Temperature Reservoirs

Summary In an ideal hydraulic fracturing project, the viscosity of hydraulic fracturing fluid (HFF) should drop to facilitate an efficient and quick fracture cleanup once proppants have been placed. Ammonium persulfate (APS) is widely used as an oxidizer breaker to degrade the insoluble residue of the HFF. However, a complex network of artificial fractures with sizes ranging from millimeters to micrometers restricts the transportation application and reaction time of standard breakers and current millimeter-sized capsule breakers. In this study, we introduce an APS nanocapsule (APS-NC) breaker, fabricated via a simple miniemulsion technique, that is capable of addressing the degradation of insoluble residue of the HFF in deep fractures. The nanocapsules are produced through precise control of the nanoprecipitation of poly(methyl methacrylate) (PMMA) onto aqueous APS nanodroplets. Stable aqueous nanodroplets are generated by means of an inverse miniemulsion using Pluronic P-123 as a specific surfactant to form a large and stable water-oil internal surface referring to the long chain and amphipathic property of Pluronic P-123 molecule. Pluronic P-123 is included in the process not only to stabilize the miniemulsion and increase the precipitation efficiency of PMMA but also to function as a thermo-responsive switch for the delayed burst release of APS. The size of the resulting nanocapsules can be controlled within the 207 and 821 nm range, yielding APS up to 92%. The release rate of APS can be controlled by the initial amount of PMMA (150–300 mg), environmental temperature (40–80°C), and environmental pH (3.4–7). When the temperature was 80℃, the initial amount of Pluronic P-123 dominated the release dynamic of APS. Compared with the APS breaker in a dynamic degradation experiment, the APS-NC had a more controllable degradation profile that could cause hydrolyzed polyacrylamide (HPAM) to burst degrade after 6 hours of heating at 80°C.

Effective Space Confinement by Inverse Miniemulsion for the Controlled Synthesis of Undoped and Eu3+-Doped Calcium Molybdate Nanophosphors: A Systematic Comparison with Batch Synthesis

Effective Space Confinement by Inverse Miniemulsion for the Controlled Synthesis of Undoped and Eu³⁺-Doped Calcium Molybdate Nanophosphors: A Systematic Comparison with Batch Synthesis

Inverse Miniemulsion Enables the Continuous-Flow Synthesis of Controlled Ultra-High Molecular Weight Polymers.

We report the controlled synthesis of ultra-high molecular weight (UHMW) polymers (Mn ≥ 106 g/mol) via continuous flow in a tubular reactor. At high monomer conversion, UHMW polymers in homogeneous batch polymerization exhibit high viscosities that pose challenges for employing continuous flow reactors. However, under heterogeneous inverse miniemulsion (IME) conditions, UHMW polymers can be produced within the dispersed phase, while the viscosity of the heterogeneous mixture remains approximately the same as the viscosity of the continuous phase. Conducting such IME polymerizations in flow results in a faster rate of polymerization compared to batch IME polymerizations while still providing excellent control over molecular weight up to 106 g/mol. Crucial emulsion parameters, such as particle size and stability under continuous flow conditions, were examined using dynamic light scattering. A range of poly(N,N-dimethylacrylamide) and poly(4-acryloylmorpholine) polymers with molecular weights of 104-106 g/mol (Đ ≤ 1.31) were produced by this method using water-soluble trithiocarbonates as photoiniferters.

Centrifugally spun hybrid polyhydroxyalkanoate/dextran nanocapsule fiber matrix for the delivery of hydrophilic payloads

Biopolymeric micro- and nanofibers with active ingredients have gained significant attention for biological applications. However, the incorporation of hydrophilic compounds into hydrophobic matrices via spinning techniques remain rather unexplored. Here we report the incorporation of dextran nanocapsules (Dex-NCs) in centrifugally spun poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) fibers for the release of hydrophilic payloads. Inverse miniemulsion polymerization was employed to synthesize hydrophilic Dex-NCs with an average size of 0.25 µm. The Dex-NCs were embedded into PHBHHx via dual solvent centrifugal spinning at 0–7 wt% loading, resulting in beaded fibers with average fiber diameters of 4–6 µm. The effect of Dex-NC loading on the melting and crystallization behavior of PHBHHx was limited, while the strength and stiffness of the hybrid fibers was retained. The elongation of the hybrid fiber mats is reduced with increasing Dex-NC loading, but remains suitable for biological applications. Further, the in vitro release measurements showed a time dependent release of embedded Dex-NCs and the payload from the hybrid fibers. We anticipate this hybrid fiber matrix to be a starting point for the development of non-woven mats for slow release of hydrophilic payloads for biological applications, especially for medical wound dressings.

RECENT TRENDS IN DIFFERENT TYPES OF SYNTHETIC HYDROPHILIC POLYMER NANOPARTICLES, METHODS OF SYNTHESIS & THEIR APPLICATIONS

Numerous types of hydrophilic polymer nanoparticles (NPs) have recently become research hotspots because of their ability to dissolve in water and can be adapted with respect to physical, chemical, and biological properties to meet the requirements of different applications. Synthetic hydrophilic polymeric NPs had successfully gained much attention because of their unique physicochemical properties, such as low toxicity, biodegradability, bioavailability, and support material for extensive swelling in water. These synthetic hydrophilic polymers NPs create new opportunities to produce water-soluble polymer types that would be able to imitate the structure and function of biological polymers. Several synthetic hydrophilic polymer NPs that gain high interest recently including poly(N-isopropyl acrylamide) (PNIPAM), poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA) and poly(N-(2-hydroxypropyl) methacrylamide (PHPMA) are reviewed in this paper. Furthermore, various synthesis methods to produce synthetic hydrophilic polymer NPs for instance emulsion polymerization, microemulsion polymerization and inverse miniemulsion polymerization are highlighted, and a brief overview on their recent applications especially in medical applications are also be discussed thoroughly in this review.

A REVIEW OF NANOGELS AS NOVEL DRUG DELIVERY SYSTEMS

The term “nanogel” refers to highly cross-linked hydrogels with a size between 20 and 200 nm. Due to their tiny size, they have higher penetration and greater drug-loading capacity. They release the medication using mechanisms such as photochemical internalization, volume transition, pH responsiveness, thermo sensitive, and photo isomerization. They can be categorized according to whether they respond to stimuli or not as well as the kind of links that are present in the gel structure’s network chains. Using photolithography, modified pollutants, and emulsions, one can create nanogel. Reverse microemulsion polymerization, inverse mini-emulsion polymerization, and the free radical cross-linking polymerization method are all examples of polymerization. Cancer, diabetes, inflammation, and bone regeneration are just a few conditions that can be treated with nanogels. The cutting-edge medication delivery technology for both hydrophilic and hydrophobic drugs is nanogels. This article focuses on the historical data regarding herbal nanogels, which have high patient compliance, delivery rate, and efficacy when used to treat various illnesses. The topic of stimulus-responsive nanogels, including pH-and temperature-responsive systems, is also covered.

Exploring the Role of Miniemulsion Nanodroplet Confinement on the Crystallization of MoO3: Morphology Control and Insight on Crystal Formation by In Situ Time-Resolved SAXS/WAXS

Enclosed nanoscale volumes, i.e., confined spaces, represent a fascinating playground for the controlled synthesis of inorganic materials, albeit their role in determining the synthetic outcome is currently not fully understood. Herein, we address the synthesis of MoO3 nano- and microrods with hexagonal section in inverse miniemulsion droplets and batch conditions, evaluating the effects of spatial confinement offered by miniemulsion droplets on their crystallization. Several synthetic parameters were systematically screened and their effect on the crystal structure of h-MoO3, as well as on its size, size distribution and morphology, were investigated. Moreover, a direct insight on the crystallization pathway of MoO3 in both synthetic conditions and as a function of synthetic parameters was provided by an in situ time-resolved SAXS/WAXS study, that confirmed the role of miniemulsion confined space in altering the stepwise process of the formation of h-MoO3.

Zwitterionic nanocapsules with pH- and thermal- responsiveness for drug-controlled release

The construction of an environmentally responsive drug-release system is of great significance for the treatment of special diseases. In particular, the construction of nanomaterials with pH- and thermal-responsiveness, which can effectively encapsulate drugs and control drug release, is becoming hot research. In this study, zwitterionic nanocapsules with stable core–shell structures were synthesized by inverse reversible addition-fragmentation transfer miniemulsion interfacial polymerization. To further study the structure and performance of the nanocapsules, the prepared nanocapsules were characterized by transmission electron microscopy, dynamic light dispersion, and zeta potential analysis. It was found that the nanocapsules had dual pH- and thermal- responsiveness, and the average particle size ranged from 178 to 142 nm when the temperature changed from 25 °C to 40 °C. In addition, bovine serum albumin (BSA) was encapsulated into nanocapsules, and sustained release experiments were conducted at 10 °C and 40 °C. The results showed that nanocapsules as carriers of BSA could achieve the purpose of sustained release of drugs, and showed different sustained release curves at different temperatures. Finally, in vitro cytotoxicity tests were performed to demonstrate the feasibility of their biomedical application. It is believed that the dual pH- and thermal- responsive nanocapsules are promising for drug-controlled release.

Facile synthesis of chromium chloride/poly(methyl methacrylate) core/shell nanocapsules by inverse miniemulsion evaporation method and application as delayed crosslinker in secondary oil recovery

Cr(III)–hydrolyzed polyacrylamide (HPAM) gels have been extensively studied as a promising strategy controlling waste water production for mature oilfields. However, the gelation time of the current technologies is not long enough for in-depth placement. In this study, we report a novel synthesis method to obtain chromium chloride/poly(methyl methacrylate) (PMMA) nanocapsules which can significantly delay the gelation of HPAM through encapsulating the chromium chloride crosslinker. The chromium chloride-loaded nanocapsules (Cr–NC) are prepared via a facile inverse miniemulsion evaporation method during which the hydrophobic PMMA polymers, pre-dispersed in an organic solvent, were carefully controlled to precipitate onto stable aqueous miniemulsion droplets. The stable aqueous nanodroplets (W) containing Cr(III) are dispersed in a mixture of organic solvent (O 1 ) with PMMA and nonsolvent medium (O 2 ) to prepare an inverse miniemulsion. With the evaporation of the O 1 , PMMA forms Cr–NCs around the aqueous droplets. The Cr–NCs are readily transferred into water from the organic nonsolvent phase. The Cr–NCs exhibit the tunable size (358–983 nm), Cr loading (7.1–19.1%), and Cr entrapment efficiency (11.7%–80.2%), with tunable zeta potentials in different PVA solution. The Cr–NCs can delay release of Cr(III) and prolong the gelation time of HPAM up to 27 days.

Design and Evaluation of Dual Release from Anacardic Acid-Based Polyurea Nanocapsules Components

Anacardic acid (AA) is a bioactive phytochemical found in the nutshell of Anacardium occidentale, a tropical plant originally from Brazil. In this work, cross-linked anacardic acid nanocapsules (NC) were obtained by interfacial polymerization carried out using the inverse miniemulsion technique with 2,4-toluene diisocyanate (TDI). For this purpose, a functionalized monomer from AA was synthesized for formation of lipase-cleavable ester linkages by coupling of amino acids. The synthesis was planned so that when these ester linkages get exposed to an enzyme, they are broken down and release AA. Furthermore, the N-termini of the coupled amino compounds were used as sites for the polyaddition with TDI at the droplet interface in the inverse miniemulsion. The permeability of the shell was studied on the fluorescent dye, sulforhodamine 101 (SR101), using fluorescence spectroscopy. After redispersion in water, the enzymatic cleavage of NC and the release of the SR101 were both monitored in real time. The released AA was proven to be active in vitro against Bacillus subtilis colonies in the bacterial tests. The results indicate that the use of NC is a promising strategy, which can make feasible the application of AA for therapeutic purposes and as nanocarriers for the delivery of active components.

Temperature-Triggered Release of Chromium Chloride from Nanocapsules for Controlled Burst Release and Gelation of Hydrolyzed Polyacrylamide to Plug High-Permeability Channels

Summary Chromium(III) (Cr3+)-hydrolyzed polyacrylamide (HPAM) gels have been applied extensively as blocking agents for sweep efficiency improvement. Previous studies focused on delaying the gelation time and ignored the diffusion of the crosslinkers during the transportation process. The gelation time of Cr3+-HPAM was too long to be controlled. This study systematically describes a novel approach of using thermoresponsive nanocapsules to precisely control the release of Cr3+. The nanocapsules are successfully prepared by a controlled nanoprecipitation of hydrophobic polymers [poly (methyl methacrylate)] (PMMA) and Pluronic® P-123 onto stable aqueous Cr3+ solution nanodroplets. The stable aqueous nanodroplets are obtained by double inverse miniemulsions with oil-soluble surfactant Span® 80. The nanoprecipitation occurs when heating the mixture at 50℃, which leads to the evaporation of solvent and precipitation of the PMMA into the interface of the aqueous droplets to form the shells. Pluronic P-123 is introduced to stabilize the double miniemulsion and enhance the precipitation efficiency of the shell polymer during the fabrication process. The fabricated nanocapsules show a size range from 211.9 to 297.2 nm depending on the feed contents of the Cr3+. The thermoresponsive function of Pluronic P-123 is studied and applied as a temperature-trigger on the shell. Gelation results show that the thermoresponsivity of Pluronic P-123 dominates the release rate rather than the diffusion rate through PMMA, which could be used to shorten the gelation interval time.

Molecularly Imprinted Ligand-Free Nanogels for Recognizing Bee Venom-Originated Phospholipase A2 Enzyme.

In this study, ligand-free nanogels (LFNGs) as potential antivenom mimics were developed with the aim of preventing hypersensitivity and other side effects following massive bee attacks. For this purpose, poly (ethylene glycol) diacrylate was chosen as a main synthetic biocompatible matrix to prepare the experimental LFNGs. The overall concept uses inverse mini-emulsion polymerization as the main route to deliver nanogel caps with complementary cavities for phospholipase A2 (PLA2) from bee venom, created artificially with the use of molecular imprinting (MI) technologies. The morphology and the hydrodynamic features of the nanogels were confirmed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis. The following rebinding experiments evidenced the specificity of molecularly imprinted LFNG for PLA2, with rebinding capacities up to 8-fold higher compared to the reference non-imprinted nanogel, while the in vitro binding assays of PLA2 from commercial bee venom indicated that such synthetic nanogels are able to recognize and retain the targeted PLA2 enzyme. The results were finally collaborated with in vitro cell-viability experiments and resulted in a strong belief that such LFNG may actually be used for future therapies against bee envenomation.

Stimuli-responsive polypeptide nanogels for trypsin inhibition.

A new type of hydrophilic, biocompatible, and biodegradable polypeptide nanogel depots loaded with the natural serine protease inhibitor α1-antitrypsin (AAT) was applied for the inhibition of the inflammatory mediator trypsin. Two types of nanogels were prepared from linear synthetic polypeptides based on biocompatible and biodegradable poly[N5-(2-hydroxyethyl)-ʟ-glutamine-ran-N5-propargyl-ʟ-glutamine-ran-N5-(6-aminohexyl)-ʟ-glutamine]-ran-N5-[2-(4-hydroxyphenyl)ethyl)-ʟ-glutamine] (PHEG-Tyr) or biocompatible Nα-ʟ-lysine-grafted α,β-poly[(2-propyne)-ᴅ,ʟ-aspartamide-ran-(2-hydroxyethyl)-ᴅʟ-aspartamide-ran-(2-(4-hydroxyphenyl)ethyl)-ᴅʟ-aspartamide] (Nα-Lys-NG). Both nanogels were prepared by HRP/H2O2-mediated crosslinking in inverse miniemulsions with pH and temperature-stimuli responsive behavior confirmed by dynamic light scattering and zeta potential measurements. The loading capacity of PHEG-Tyr and Nα-Lys-NG nanogels and their release profiles were first optimized with bovine serum albumin. The nanogels were then used for loading and release of AAT. PHEG-Tyr and Nα-Lys-NG nanogels showed different loading capacities for AAT with the maximum (20%) achieved with Nα-Lys-NG nanogel. In both cases, the nanogel depots demonstrated a burst release of AAT during the first 6 h, which could be favorable for quick inhibition of trypsin. A consequent pilot in vitro inhibition study revealed that both PHEG-Tyr and Nα-Lys-NG nanogels loaded with AAT successfully inhibited the enzymatic activity of trypsin. Furthermore, the inhibitory efficiency of the AAT-loaded nanogels was higher than that of only AAT. Interestingly, also non-loaded PHEG-Tyr and Nα-Lys-NG nanogels were shown to effectively inhibit trypsin because they contain suitable amino acids in their structures that effectively block the active site of trypsin.

Charge-reversible and biodegradable chitosan-based microgels for lysozyme-triggered release of vancomycin

IntroductionHigh-dose drug administration for the conventional treatment of inflammatory bowel disease induces cumulative toxicity and serious side effects. Currently, few reports have introduced smart carriers for intestinal inflammation targeting toward the treatment of inflammatory bowel disease. ObjectivesFor the unique lysozyme secretory microenvironment of the inflamed intestine, vancomycin-loaded chitosan-polyaniline microgels (CH-PANI MGs) were constructed for lysozyme-triggered VM release. MethodsAniline was first grafted to chitosan to form polymers that were crosslinked by glutaraldehyde to achieve CH-PANI MGs using the inverse (water-in-oil) miniemulsion method. Interestingly, CH-PANI MGs exhibit polyampholyte behaviour and display charge-reversible behaviour (positive to negative charges) after treatment with a NaCl solution. ResultsThe formed negatively charged N-CH-PANI MG aqueous solution is employed to load cationic vancomycin with a satisfactory loading efficiency of 91.3%, which is significantly higher than that of chitosan-based MGs. Moreover, N-CH-PANI MGs present lysozyme-triggered biodegradation and controllable vancomycin release upon the cleavage of glycosidic linkages of chitosan. In the simulated inflammatory intestinal microenvironment, vancomycin is rapidly released, and the cumulative release reaches approximately 76.9%. Remarkably, N-CH-PANI@VM MGs not only exhibit high resistance to harsh gastric acidity but also prevent the premature leakage of vancomycin in the healthy gastrointestinal tract. Encouragingly, the N-CH-PANI@VM MGs show obvious antibacterial activity against Staphylococcus aureus at a relatively low concentration of 20 μg/mL. ConclusionCompared to other pH-responsive carriers used to treat inflammatory bowel disease, the key advantage of lysozyme-responsive MGs is that they further specifically identify healthy and inflammatory intestines, achieving efficient inflammatory bowel disease treatment with few side effects. With this excellent performance, the developed smart MGs might be employed as a potential oral delivery system for inflammatory bowel disease treatment.

Multicomponent encapsulation into fully degradable protein nanocarriers via interfacial azide-alkyne click reaction in miniemulsion allows the co-delivery of immunotherapeutics.

Encapsulation of multiple adjuvants along with antigens into nanocarriers allows a co-delivery to antigen-presenting cells for the synergistic induction of robust immune responses. However, loading cargoes of different molar masses, polarities, and solubilities in high efficiencies remains a challenge. Therefore, we developed a strategy to encapsulate a triple combination of the so-called adjuvants, i.e. with Resiquimod (R848), muramyl dipeptide (MDP) and polyinosinic-polycytidylic acid (Poly(I : C)) into human serum albumin (HSA) nanocarriers. The loading is conducted in situ while the nanocarrier is formed by an orthogonal and metal-free click reaction at the interface of an inverse miniemulsion. By this unique approach, high encapsulation efficiency without harming the cargo during the nanocarrier formation process and regardless of their physical properties is achieved, thus keeping their bioactivity. Furthermore, we demonstrated high control over the encapsulation efficiency and varying the amount of each cargo did not influence the efficiency of multicomponent encapsulation. Azide-modified HSA was crosslinked with hexanediol dipropiolate (HDDP) at the interface of a water-in-oil miniemulsion. Varying the crosslinker amount allowed us to tailor the density and degradation rates of the protein shell. Additional installation of disulfide bonds into the crosslinker created redox-responsive nanocarriers, which degraded both by protease and under reducing conditions with dithiothreitol. The prepared HSA nanocarriers were efficiently taken up by dendritic cells and exhibited an additive cell activation and maturation, exceeding the nanocarriers loaded with only a single drug. This general protocol allows the orthogonal and metal-free encapsulation of various drugs or adjuvants at defined concentrations into the protein nanocarriers.

Core–shell microgels having zwitterionic hydrogel core and temperature-responsive shell prepared via inverse miniemulsion RAFT polymerization

The temperature-responsive core–shell microgels comprising PMPC core and side-chain oligo(ethylene glycol) polymer shell were prepared via inverse miniemulsion RAFT polymerization using a water-soluble emulsifier with RAFT agent terminus.

Comparison of carboxybetaine with sulfobetaine polyaspartamides: Nonfouling properties, hydrophilicity, cytotoxicity and model nanogelation in an inverse miniemulsion

AbstractZwitterionic polymers are promising non‐fouling materials widely used for surface modification. Here, we report the synthesis of zwitterionic polyaspartamides bearing carboxybetaine and sulfobetaine prepared via combining the ring‐opening reaction of polysuccinimide with 3‐(dimethylamino)‐1‐propylamine and the reaction of the formed tertiary amine side groups with 1,3‐propanesultone and 4‐bromobutyric acid, respectively. Both sulfobetaine and carboxybetaine polyaspartamides have cationic and anionic charged groups on the same repeat unit, but they differ in negatively charged groups. The chemical structures of the synthesized polymers were confirmed by 1H NMR and FT‐IR spectroscopies. The zwitterionic property of polyaspartamides were characterized by zeta potential measurements using wide range of pH. The surface properties mainly anti‐protein adsorption abilities and hydrophilicity were tested by surface plasmon resonance analysis, fluorescence microscopy, and contact angle measurements. Importantly, sulfobetaine polyaspartamides demonstrated better both antifouling performance and ability to form more hydrophilic surfaces than carboxybetaine polyaspartamide. Two zwitterionic carboxybetaine and sulfobetaine nanogels were prepared by horseradish peroxidase‐mediated crosslinking in an inverse miniemulsion. Results from dynamic light scattering and transmission electron microscopy showed the formation of nanosized spherical particles. Additionally, sulfobetaine and carboxybetaine polyaspartamides had remarkable biocompatibilities, indicating their promise as non‐fouling materials for biomedical applications.

Preparation of quaternized chitosan/Ag composite nanogels in inverse miniemulsions for durable and antimicrobial cotton fabrics

It is an urgent task to exploit effective antimicrobial agents due to the rise of drug-resistant pathogens. Herein, antimicrobial quaternized chitosan/Ag composite nanogels (QCS/Ag CNGs) with tunable properties were fabricated through inverse miniemulsion technique with a high encapsulation efficiency of NH2-Ag nanoparticles (NPs). The QCS/Ag CNGs possess superior broad-spectrum antimicrobial activity and low biotoxicity, via synergistic sterilization of Ag NPs and QCS. Furthermore, the NH2-Ag NPs were chemically linked to the QCS matrix through Schiff base reactions, and the QCS/Ag CNGs have reactive groups, making it possible to obtain durable antibacterial cotton fabrics. Thus, QCS/Ag CNGs modified cotton fabrics exhibited laundering durability of antimicrobial effect after 100 washing cycles without sacrificing other inherent properties of cotton fabrics. Our study provides a facile and controllable method to construct polymer/inorganic CNGs to address the urgent need for antibacterial agents/fabrics.