Temperature stimuli-responsive nanoparticles from chitosan-graft-poly(N-vinylcaprolactam) as a drug delivery system

This work describes the preparation of thermosensitive chitosan-graft-poly(N-vinylcaprolactam) nanoparticles by ionic gelation and their potential use as a controlled drug delivery system, using doxorubicin as a model drug. A systematic study of the effect of the main processing parameters on both the size and thermoresponsive behavior of nanoparticles was investigated. The size of the particles is strongly dependent on the length of the poly(N-vinylcaprolactam) grafted chains and the concentration of the copolymer and crosslinking agent solutions. The molecular structure of the copolymer plays an essential role in the phase transition temperature of the particles, which decreases with the length of PVCL grafted chain. The system displayed proper drug-association parameters, and the drug-loaded nanoparticles exhibited dose-dependent cytotoxicity. A significant increase in the doxorubicin delivery rate was observed above the phase transition temperature (40 °C). These features indicate that these nanoparticles are suitable for the development of a new thermally controlled anti-cancer drug delivery system. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47831.     

p(AAm/TA)‐based IPN hydrogel films with antimicrobial and antioxidant properties for biomedical applications

Interpenetrating polymer networks (IPN), either semi‐IPN (s‐IPN) or full IPN, based on a natural polymer tannic acid (TA) and synthetic poly(acrylamide) (p(AAm)) were prepared by incorporation of TA during p(AAm) hydrogel film preparation with and without crosslinking of TA simultaneously. The synthesis of p(AAm/TA) s‐IPN and IPN hydrogels with different amounts of TA were prepared by concurrent use of redox polymerization and epoxy crosslinking. The p(AAm)‐based hydrogels were completely degraded at 37.5°C within 9 and 2 days at pHs 7.4 and 9, respectively. Biocompatibility of p(AAm), s‐IPN, and IPN were tested with WST assay and double staining, they had 75% cell viability up to almost 20 μg mL^?1 concentration against L929 fibroblast cell. Antioxidant properties of IPN and s‐IPN hydrogels were investigated with FC and ABTS^? methods. Antimicrobial properties of TA‐containing s‐IPN, and IPN hydrogels were determined against three common bacterial strains, Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 6538, and Bacillus subtilis ATCC 6633, and it was found that p(AAm/TA)‐based s‐IPN and IPN hydrogels are effective antimicrobial and antioxidant materials. Moreover, almost up to day‐long linear TA release profiles were obtained from IPN and s‐IPN hydrogels in phosphate buffer solution at pH 7.4 at 37.5°C. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41876.     

Chitosan hydrogel covalently crosslinked by gold nanoparticle: Eliminating the use of toxic crosslinkers

Tissue engineering has directed a lot of effort toward the development of devices with suitable biocompatibility and mechanical properties. Chitosan has been pointed as a valuable material to be applied in scaffolds due to its antimicrobial activity and biocompatibility. Nevertheless, the low mechanical resistance associated with the requirement of toxic crosslinkers has hampered translational application of chitosan hydrogel. Herein, the use of gold nanoparticles (AuNP) as crosslinker is reported as a great strategy to obtain chitosan hydrogel without using toxic reactants. In addition, the resultant chitosan hydrogel, crosslinked by AuNP of 30 nm (AuNP30), presented outstanding properties compared to chitosan hydrogel crosslinked by glutaraldehyde. Chitosan hydrogel crosslinked by AuNP30 presented lower porosity, which provided lower swelling degree and slower degradation rate. In addition, compressive strength was about two times higher than the chitosan hydrogel crosslinked by glutaraldehyde. The crosslink by AuNP30 also increased the biocompatibility of the hydrogel. Chitosan hydrogel crosslinked by AuNP30 did not show cytotoxicity against MEF cells, whereas cell viability of cells incubated with extract from chitosan hydrogel crosslinked by glutaraldehyde was only 41%. In conclusion, the results reported herein pointed that the use of AuNP30 as crosslinker agent provided to chitosan hydrogel enhanced properties that made it suitable to application in biomedical devices.     

Reactive red 120 and NI(II) derived poly(2‐hydroxyethyl methacrylate) nanoparticles for urease adsorption

Non‐porous poly(2‐hydroxyethyl methacrylate) [p(HEMA)] nanoparticles were prepared by surfactant free emulsion polymerization. The p(HEMA) nanoparticles was about 200 nm diameter, spherical form, and non‐porous. Reactive Red 120 (RR 120) was covalently attached to the p(HEMA) nanoparticles and Ni(II) ions were incorporated to attach dye molecules. Urease was immobilized onto RR120‐Ni(II) attached p(HEMA) nanoparticles via adsorption. The maximum urease adsorption capacity of RR120‐Ni(II) attached p(HEMA) nanoparticles was 480.01 mg g^?1 nanoparticles at pH 7.0 in phosphate buffer. It was observed that urease could be repeatedly adsorbed and desorbed without significant loss in adsorption amount. K_m values were 21.50 and 34.06 mM for the free and adsorbed enzyme. The V_max values were 4 U for the free enzyme and 3.3 U for the adsorbed enzyme. The optimum pH was 25 mM pH 7 phosphate buffer for free and adsorbed enzyme. The optimum temperature was determined at 35°C and 55°C for the free and adsorbed enzyme, respectively. These findings show considerable promise for this material as an adsorption matrix in biotechnological applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39757.     

Enhanced function of chondrocytes in a chitosan-based hydrogel to regenerate cartilage tissues by accelerating degradability of the hydrogel via a hydrolysable crosslinker

Chitosan-based hydrogels as scaffolds for culturing chondrocytes were prepared using linkers with and without hydrolysable poly(dl -lactide) (PLA) segments. The evaluation of the cultured chondrocytes in them indicated that the accelerated degradation of the hydrogel via hydrolysis of the PLA slightly promoted production of the sulfated glycosaminoglycan and drastically improved that of collagen from the encapsulated chondrocytes, which are the chondrospecific extracellular matrix components. Furthermore, the accelerated degradability significantly upregulated the gene expression for Collagen II production and downregulated that for Collagen I production of the encapsulated chondrocytes. Because major component of the articular cartilage tissue is Collagen II-rich hyaline cartilage, these results suggest the degradation of the scaffolds is an important parameter in cartilage tissue regeneration and the accelerated degradability may have benefits on promotion of cartilage tissue regeneration especially from the viewpoint of hyaline cartilage-like collagen production. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48893.     

Antibacterial and antifungal dressings obtained by photochemical deposition of silver nanoparticles

The antimicrobial activity of silver against a wide spectrum of bacteria, fungi and viruses is known since antiquity. Silver has been used as topical antimicrobial agent in the treatment of wounds since many years and advanced silver‐based dressings have been designed so far. The aim of this study was the development of low‐cost antibacterial and antifungal dressings through the surface modification of conventional cotton gauzes. Different percentages of silver were deposited on textile substrates by adopting an innovative silver deposition technique based on the photochemical deposition of silver nanoparticles. The uniformity of the coating and the distribution of the silver clusters on the surface were evaluated by scanning electron microscopy (SEM). The amount of silver was quantified by thermogravimetric analysis (TGA) and the presence of metallic silver nanoparticles was also assesses through UV–Vis–NIR with integrating sphere and energy dispersive X‐ray spectroscopy EDX. The effectiveness of the silver treated textile was verified on different microorganisms, namely Escherichia coli, Staphylococcus aureus, Pseudomonas p43 and Candida albicans derived from a clinical isolate. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40326.     

Physicomechanical and antimicrobial characteristics of hydrogel based on poly(vinyl alcohol): Performance improvement via inclusion of chitosan-modified nanoclay

The effect of a chitosan-modified nanoclay (CMNC) on the physical, mechanical, and antimicrobial properties of poly(vinyl alcohol) (PVA) hydrogels prepared by the electron beam irradiation method is reported in comparison with pristine nanoclay (PNC). The X-ray diffraction (XRD) results confirm that the chitosan modification process of nanoclay led to an enhancement in the clay gallery spacing. The inclusion of nanoclays in the PVA matrix decreased the gel content while it increased the swelling degree of the hydrogels. Both PNC and CMNC played a role, depending on their amounts, in swelling of the hydrogel. The swelling kinetic studies revealed a diffusion-controlled swelling process. The diffusion coefficient of water molecules in hydrogels was decreased in the presence of PNC, while it increased with CMNC. Rheological investigations verified the influential role of nanoclays in decreasing the chemical crosslink density of the hydrogel. CMNC exhibited a higher reinforcing effect on hydrogel mechanical properties than PNC did, although the rheological analysis, in agreement with the XRD results, indicated a better dispersion of PNC in the PVA matrix. According to the antimicrobial tests, perfect inhibition of bacteria growth was obtained only for the hydrogels with CMNC. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47444.     

GSH-responsive polyglutamic acid nanocarriers for dual targeted cancer therapy

In order to reduce the toxic side effects of chemotherapeutic drugs and improve the targeting and efficiency of cancer treatment, the development of drug delivery system has received great attention. In this study, second generation polyglutamic acid dendrimers (G₂) are used as basic materials to produce porous nanoparticles through cross link by crosslinkers containing disulfide bonds. The crosslinked products (G₂)_n have negative electricity and abundant voids, which enable them to adsorb the electronegative anticancer drug DOX. At the same time, in order to transport DOX to the tumor site, we modified FA on DOX and encapsulated it in magnetic mesoporous silica (FA-DOX-MSNs). Therefore, the final nanoparticles (FA-DOX-MSNs/(G₂)_n) not only have dual targeting ability to transport DOX to the tumor site, but also have reductive responsiveness that can release drugs responsively in the tumor cells. In addition, it has good biocompatibility and endocytosis ability.     

pH‐sensitive keratin‐based polymer hydrogel and its controllable drug‐release behavior

Using feather keratin as biocompatible and inexpensive natural biopolymer and methacrylic acid as a functional monomer, we prepared a pH‐sensitive feather‐keratin‐based polymer hydrogel (FKPGel) with grafted copolymerization. The obtained FKPGel was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The swelling behavior and pH sensitivity of the FKPGel were investigated. When the small molecule (rhodamine B) and macromolecule (bovine serum albumin) were used as model drug molecules, the FKPGel exhibited controllable release behavior in vitro, and the hydrogels had pH sensitivity. For a small molecular drug, the cumulative release rate was 97% in 24 h at pH 8.4. For macromolecular drug, the cumulative release rate reached 89% at pH 7.4. Its release behavior could be controlled by the pH value. In summary, a simple method was found to reuse disused feathers. It is a kind of pH‐sensitive hydrogels to be applied in drug‐delivery systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41572.     

Improving the metal ion release from nanoparticles embedded in a polypropylene matrix for antimicrobial applications

Novel antimicrobial materials can be produced by adding copper nanoparticles (CNPs) into a polymeric matrix. To improve the behavior of these systems, the effect of different variables on the dispersion of copper metal nanoparticles embedded in a polypropylene matrix by melt mixing and its ion release was analyzed. The variables studied were predispersion of particles in liquid solvents, polymer molecular weight, melt mixing conditions, addition of a compatibilizer agent, two‐step melt mixing, and surface functionalization of the metal particles. Our results show that by modifying these variables, a significant improvement in the filler dispersion, as quantified by optical microscope, can be obtained. For instance, the original CNP agglomerates can be reduced from an average size of 70 µm to a final average size of 30 µm and a larger amount of nanometric agglomerates by using a compatibilizer or predispersed nanoparticles. Moreover, by using surface‐functionalized CNPs, micrometric agglomerates were not observed. Noteworthy, there is a direct relationship between the filler dispersion and the release of biocide copper ions when improvements were larger than a certain threshold with increases as high as 40%. These findings can be used in the development of antimicrobial materials with tailored behavior. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41232.     

Design and characterization of pH stimuli-responsive nanofiber drug delivery system: The promising targeted carriers for tumor therapy

New carrier platforms have been designed for an electrospun pyridinium calixarene nanofiber for controlled drug delivery. First, 5,11,17,23-tetra-tert-butyl-25,27-bis(3-aminomethyl-pyridineamido)-26,28-dihydroxycalix[4]arene (3-AMP) scaffold was produced by electrospinning. AMP scaffold was modified by human serum albumin (HSA), folic acid (FA), and glutathione (GSH). Doxorubicin (DOX) was loaded to surfaces of the AMP, AMP-HSA, AMP-HSA-FA, and AMP-HSA-GSH nanofibers by using DOX solution in different buffers with, 2.2, 4.0, 6.0, and 7.4 pH. The release studies DOX from four different nanofibers was also done in a various amount microenviroments by changing pH values. The loading and release amount of DOX was estimated from the calibration curve drawn at 480 and 560 nm of excitation and emission wavelengths by using a fluorescence spectrophotometer. The loading studies were confirmed by Fourier transforms infrared, atomic force microscopy, transmission electron microscopy, scanning electron microscope, and energy-dispersive X-ray (EDX) analysis.     

Fabrication of galactosylated chitosan–5‐fluorouracil acetic acid based nanoparticles for controlled drug delivery

In this study, a novel type of macromolecular prodrug, N‐galactosylated chitosan (GC)?5‐fluorouracil acetic acid (FUA) conjugate based nanoparticles, was designed and synthesized as a carrier for hepatocellular carcinoma drug delivery. The GC–FUA nanoparticles were produced by an ionic crosslinking method based on the modified ionic gelation of tripolyphosphate with GC–FUA. The structure of the as‐prepared GC–FUA was characterized by Fourier transform infrared and ¹H‐NMR analyses. The average particle size of the GC–FUA nanoparticles was 160.1 nm, and their drug‐loading content was 21.22 ± 2.7% (n = 3). In comparison with that of the freshly prepared nanoparticles, this value became larger after 7 days because of the aggregation of the GC–FUA nanoparticles. An in vitro drug‐release study showed that the GC–FUA nanoparticles displayed a sustained‐release profile compared to 5‐fluorouracil‐loaded GC nanoparticles. All of the results suggest that the GC–FUA nanoparticles may have great potential for anti‐liver‐cancer applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42625.     

Radiopaque iodinated ethers of poly(vinyl iodobenzyl ether)s: Synthesis and evaluation for endovascular embolization

Leachable‐free radiopaque iodinated polymers were designed as long‐lived embolization materials visible by X‐ray tomography. This is a definite improvement over liquid embolics incorporating either radiopaque inorganic particles or iodinated polymers having hydrolysable ester bonds. Grafting 4‐iodobenzyl or 2,3,5‐triiodobenzyl groups to poly(vinyl alcohol) (PVAL) yields iodobenzyl ethers of PVAL having iodine contents in the range 40–70 wt %. Their solubility in solvents accepted for medical devices (DMSO and NMP), viscosity of concentrated solutions, precipitation behavior, radiopacity, and stability with respect to sterilization and hydrolysis were assessed. The solvent NMP allows the preparation of concentrated solutions of suitable viscosity for their application as liquid embolics. Precipitation in water yields a cohesive mass of material that can plug vascular malformations. A rationale to the properties is given in terms of the Hansen contributions to the Hildebrand solubility parameters. Iodobenzyl ethers of PVA resist hydrolysis whereas their corresponding iodobenzoyl esters leach iodinated fragments. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41791.     

Multi stimuli-responsive HPC-PAA/Eu(AA)3Phen complex nanogels and their decoration with 3-APBA for detecting glucose

In this paper, novel multi stimuli-responsive complex nanogels of hydroxypropylcellulose (HPC)-PAA/Eu(acrylic acid [AA])₃Phen were synthesized by radical polymerization method with HPC, rare earth complex (Eu(AA)₃Phen) and AA as raw materials, and the 3-aminophenylboronic acid (3-APBA) decorated nanogels (HPC-PAAPBA/Eu(AA)₃Phen) were fabricated via condensation of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride with 3-APBA. The microstructure, morphology and diameter of the nanogel were characterized by Fourier transform infrared spectrometer, UV–Visible spectrophotometer, transmission electron microscope, dynamic light scattering. Moreover, the fluorescence responsive performance of complex nanogels to temperature, pH value and glucose concentration was investigated by photoluminescence spectroscopy. The results showed that both of the as-prepared nanogels were uniform in size and had good monodispersity. The temperature and pH value had significant effects on the particle size and the fluorescence emission intensity of the HPC-PAA/Eu(AA)₃Phen complex nanogels; after decoration with 3-APBA, the obtained HPC-PAAPBA/Eu(AA)₃Phen nanogels showed excellent stimulus-response to glucose concentration.     

Preparation,characterization, and properties of modified barium sulfate nanoparticles/polyethylene nanocomposites as T‐shaped copper intrauterine devices

To improve the mechanical properties and shelf‐life of barium sulfate nanoparticles (BaSO₄‐NPs)/polyethylene (PE) composites, which are used as the scaffold of T‐shaped copper intrauterine devices (Cu‐IUDs) in the clinic, an Al coupling agent was used to modify BaSO₄‐NPs. The influence of the Al coupling agent on the microstructures, properties, and shelf‐life of the nanocomposites were investigated. The results showed that: (1) a chemical reaction occurred between the Al coupling agent and the hydroxyl groups adsorbed by BaSO₄‐NPs. (2) BaSO₄‐NPs modified by the Al coupling agent dispersed in the PE matrix were much better than unmodified NPs. The interface bonding between modified NPs and the PE matrix was better than unmodified NPs. (3) the maximum tensile strength of nanocomposites containing modified NPs was 11.87 MPa, flexural strength was 6.61 MPa, and the elongation rate was 66.78%. (4) After an accelerated aging experiment, the tensile strength of the nanocomposites only decreased 5–15%. All of these results indicate that m‐BaSO₄‐NPs/PE nanocomposites are more clinically useful than unmodified nanocomposites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40393.     

Analyzing the interactions and miscibility of silk fibroin/mucin blends

Mucin, a glycoprotein with viscoelastic properties, and silk fibroin, a protein excreted from silkworms with properties of thermal and mechanical resistance, have been probed as building blocks in the design of biomaterials. Aiming to evaluate the interaction and miscibility between mucin and fibroin, we synthesized silk fibroin and mucin (SF/MU) blends for biomedical applications. The morphological analysis of the SF/MU blends showed the presence of two phases, suggesting a partial miscibility between the polymers. The degradation temperature of the SF/MU blends increased with an increase in the silk fibroin content, indicating that silk fibroin contributed to the thermal stability of the blends. The glass transition temperature of the SF/MU blends lay between the values of the pure polymers. The Fourier-transform infrared spectroscopy results pointed out that the interaction between fibroin and mucin occurred between the amine group of silk fibroin and mucin carboxyl and hydroxyl groups. The outcomes of this work provided essential information on the miscibility of the SF/MU blends. These findings will be critical for further studies with fibroin and mucin-based biomaterials, especially in mucoadhesive systems and wound healing applications.     

Development and characterization of a poly (vinyl alcohol) and sodium alginate blend foam for wound dressing loaded with propolis and all-trans retinoic acid

Propolis is a complex mixture of phytochemicals, with antibacterial, anti-inflammatory, and healing properties. All-trans retinoic acid is implicated in wound healing by stimulating angiogenesis, cell recruitment, extracellular matrix deposition, and reepithelization. The incorporation of both agents to a polymeric wound dressing composed of poly (vinyl alcohol) and sodium alginate may result in improved healing allied to controlled release, fluid uptake, and wound protection. In the present work, we have physically characterized this wound dressing and analyzed its release kinetics. The anti-inflammatory capacity was assayed. SEM images showed a highly porous structure with a diverse morphology. FTIR spectra displayed a highly cross-linked structure with both polymers connected by hydrogen bonds and acetal bridges. The wound dressings were able to retain great volumes of PBS. Propolis and vitamin A releasing behavior were maintained for 6 h. The concentrations of the biologically active substances were capable of promoting anti-inflammatory action in an erythrocyte membrane stabilization model. The wound dressings obtained here showed adequate physical properties. The fabrication process did not affect the anti-inflammatory capacity. Further tests are needed to ensure the biocompatibility and to assess other biological activities of the therapeutic agents.     

Microporous PDMAEMA‐based stimuli‐responsive hydrogel and its application in drug release

The microporous hydrogels (Pn‐Cm gels) composed of poly(dimethylaminoethyl methacrylate) and carboxymethylchitosan were synthesized in situ radical polymerization by using nano γ‐Fe₂O₃ particles as pore‐agent. The microporous structure formed through eliminating the Fe₂O₃ particles was designed to achieve a faster response rate and better drug loading effect. Comparing to the neat gels, Pn‐Cm gels exhibit deteriorative mechanical properties with the increased pores, while the gels still keep the elastic network structure which could bear some degree of tensile and compression deformation. Meantime, Pn‐Cm gels show similar temperature and pH double responsiveness with same isoelectric point shrink as that of neat gels, the swelling ability decreases slightly, and the deswelling rate increases with the increase of pores. Moreover, the 5‐fluorouracil was used as a target drug to explore the potential of this gel applied as drug‐release system. For Pn‐Cm gels, the more pores and carboxymethyl chitosan inside the gels are beneficial to the drug loading, all gels show a burst release of drug, being followed by a slow and sustained release with different rate. Comprehensively, the Pn‐Cm gels exhibit a better sustained release effect in the simulated stomach condition (pH = 2.1), the related release mechanism could be interpreted by the superposition of Fickian diffusion. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45326.     

Preparation of hydrogel impregnated antimicrobial polyurethane foam for absorption of radionuclide contaminated blood and biological fluids

Multi‐purpose polyacrylamide (PAM) and polyacrylamide‐co‐sodiumpolyacrylate (PAM‐co‐NaPA) impregnated polyurethane foams (PUF) loaded with iodine have been prepared by in situ free radical polymerization. The prepared hydrogel networks displayed higher capacity for absorbing biological fluids as compared to regular PUF sheets and cotton matrices used in hospitals for maintaining hygiene conditions in cases of blood spillage and leakages. PAM‐impregnated‐PUF showed 910, 605, and 172% absorption in water, saline, and blood, respectively, whereas PAM‐co‐NaPA‐impregnated‐PUF showed absorption of 1545, 1395, and 269% in water, saline, and blood, respectively in 24 h. Exposure to nuclear, biological, and chemical (NBC) environment has become a grave predicament in today's world necessitating prevention of radiological contaminations especially in medical facilities. PAM‐co‐NaPA‐impregnated‐PUF displayed 97% absorption of Tc⁹⁹ from whole blood whereas PUF sheets were highly hydrophobic and showed only 1% absorption of Tc⁹⁹ from whole blood. It was also demonstrated that modified foams have long‐term broad‐spectrum antimicrobial properties due to sustain release of ionic iodine. Thus, PAM‐co‐NaPA‐impregnated‐PUF sheets have strong potential to be used as matrices for carrying the injured patients, from field conditions to hospitals expose to NBC environment. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43625.     

Antibacterial properties of polyaniline derivatives

This work presents a detailed study on the effect of various functional groups both at the ortho position of the aromatic ring and in the amino group of PANI on the antibacterial properties of polymers against gram-positive (Bacillus subtilis) and gram-negative (Pseudomonas aureofaciens) microorganisms. It was found that incorporation of methyl, methoxy, or pentyl groups into the ortho-position of PANI did not increase the antibacterial activity but in most cases causes a significant decrease in the antibacterial properties of functionally substituted polyanilines. At the same time, PANI derivatives modified by incorporation of pentyl groups into the amino group were found to be more efficient antibacterial compounds against both gram-positive and gram-negative microorganisms than the original polymer. It was also found that N-substituted PANI derivatives manifest not only bactericidal but also bacteriostatic properties toward the test microorganisms. Varying the nature and position of the substituent allowed us to conclude that the synthesis of various N-substituted PANI derivatives with a high degree of doping is the most promising approach to PANI modification for application in bacterial growth inhibition.