Grafting Of Poly Research Articles

PH-Responsive Copolymeric Network Gel Using Methacrylated β-Cyclodextrin for Controlled Codelivery of Hydrophilic and Hydrophobic Drugs

In medical science, sometimes two drugs with different solubilities are simultaneously required in combination to treat various diseases. Herein, a pH-responsive, copolymeric, antioxidant, biocompatible, and chemically crosslinked network gel is prepared to explore its capability as a matrix for controlled release of both hydrophobic [ibuprofen (IB)] and hydrophilic [tetracycline hydrochloride (TCH)] drugs, simultaneously. This three-dimensional β-CD-Meth-cl-(PHPMA-co-PAAc) network hydrogel is synthesized via two steps: (I) methacrylation of β-cyclodextrin and (II) grafting of poly(hydroxypropyl methacrylate) and poly(acrylic acid), followed by crosslinking of poly(ethylene glycol) diacrylate onto the backbone of methacrylated β-cyclodextrin (β-CD-Meth). The successful synthesis of the hydrogel is confirmed using several physiochemical characterizations. The β-CD-Meth-cl-(PHPMA-co-PAAc) hydrogel has an excellent network-like surface morphology. The potential pH-responsive high swelling behavior and excellent shrinking features suggest the reversible nature of the synthesized gel. Besides, rheological analyses affirm its excellent viscoelastic nature. This network gel is biodegradable and its non-cytotoxic nature toward human dermal fibroblast cells is demonstrated. Moreover, the dual drug release pattern from the copolymer under both in vitro and in vivo conditions portrays that this hydrogel has superior ability to be used as a controlled release matrix for both hydrophobic and hydrophilic drugs (TCH and IB) with varying solubilities concurrently.

Synthesis of Amine Grafted Poly (Acrylic-Maleic) as an efficient inhibitor against stainless steel corrosion in a highly saline medium

In this study, a novel amine grafted poly-(acrylic maleic) (APAM) was synthesized and its efficiency was investigated against the corrosion of stainless steel 316 L in simulated saline (3.5 % NaCl) environment using electrochemical and weight loss experiments at various temperatures i.e. 25, 40 and 60 °C. The synthesized compound was characterized by FTIR, proton, and carbon-13 NMR techniques. The compound performed excellently and was observed to function as a mixed-type inhibitor, inhibiting both the cathodic hydrogen evolution and anodic iron dissolution reactions. The adsorption of APAM molecules obeyed the Langmuir adsorption theory and the estimated values of ∆Gado obtained using weight and PDP data suggest that APAM adsorbed on the steel surface by both the chemisorption and physiosorption mechanisms. APAM molecules adsorbed to the steel surface to create an APAM layer that inhibits the corrosive medium from reaching the surface, according to surface morphological observations and examination of the protected steel surface using SEM, EDS, AFM, and FTIR spectra.

Fabrication of Electrospun Xylan-g-PMMA/TiO2 Nanofibers and Photocatalytic Degradation of Methylene Blue.

Herein, xylan-g-PMMA was synthesized by grafting poly(methyl methacrylate) (PMMA) onto xylan and characterized by FT-IR and HSQC NMR spectroscopies, and the xylan-g-PMMA/TiO2 solution was used to electrospun nanofibers at the voltage of 15 Kv, which was the first time employing xylan to electrospun nanofibers. Moreover, the electrospinning operating parameters were optimized by assessing the electrospinning process and the morphology of electrospun fibers, as follows: the mixed solvent of DMF and chloroform in a volume ratio of 5:1, an anhydroxylose unit (AXU)/MMA molar ratio lower than 1:2, the flow speed of 0.00565–0.02260 mL/min, and a receiving distance of 10–15 cm. Diameters of the electrospun fibers increased with increasing DMF content in the used solvent mixture, MMA dosage, and receiving distance. TiO2 nanoparticles were successfully dispersed in electrospun xylan-g-PMMA nanofibers and characterized by scanning electron microscopy, energy dispersive X-ray diffraction spectrum, and X-ray photoelectron spectroscopy, and their application for methylene blue (MB) degradation presented above 80% photocatalytic efficiency, showing the good potential in water treatment.

Grafting of poly(lactic acid) by cyclodextrin extrusion reaction and its foaming properties

Grafting of poly(lactic acid) by cyclodextrin extrusion reaction and its foaming properties

Scavenging of hexavalent chromium from aqueous solution by Macadamia nutshell biomass modified with diethylenetriamine and maleic anhydride

Based on the premise that aqueous anions of hexavalent chromium (Cr(VI)) are capable of electrostatic interaction with cationic and polar active sites, acid-washed Madacamia nutshell biomass was sequentially treated with diethylenetriamine (DETA) and maleic anhydride (MA) to graft poly(diethylenetriamine–co–maleic anhydride). By displaying a new peak at 1685 cm−1 ascribed to amide CO stretching vibrations, Fourier transform infrared spectroscopy highlighted the formation of amide groups through reaction of DETA with carboxyl groups on the biomass surface. Scanning electron microscopic images of the MA-modified biomass displayed polymeric growths attributed to copolymerization of DETA with MA. The polar and ionizable amide and amine groups of the grafted copolymer endowed the adsorbent with Cr(VI) removal capabilities over a wide pH range demonstrated by removal efficiencies between 70.9% and 81.7% in the pH 1.6 to pH 10.0 range for the treatment of 20 mL solutions containing 100 mg L−1 Cr(VI) with 200 mg of adsorbent. Conformity of the adsorption isotherm data to the Freundlich model revealed the heterogeneous nature of the adsorbent surface, which comprised a variety of functional groups capable of interaction with Cr(VI) species in solution. The Sips isotherm model provided the best fit to the equilibrium experimental data, and the adsorption capacity was 779.1 mg g−1 at pH 1.6, room temperature and an adsorbent dosage of 5.0 g L−1. The findings indicate that Cr(VI) adsorption onto diethylenetriamine and maleic anhydride modified Madacamia nutshell biomass is a promising option for Cr(VI) removal from aqueous solutions.

Brush-Structured Chitosan/PolyHEMA with Thymine and Its Synergistic Effect on the Specific Interaction with ssDNA and Cellular Uptake.

Cationic polymers are known to attach on an anionic cell surface and favor gene transportation/transfection into the cells. However, when the positive charges accumulate, they tend to cause cell damage and delivery failure. Chitosan (CS) is a potential cationic bio-derived polymer whose chemical structures can be modified to fine-tune the charges as well as the add-on functions. The present work demonstrates (i) the decoration of a nucleic acid sequence-like brush structure on CS to allow the specific interaction with DNA and (ii) delivery into the cell. By simply applying mercaptoacetic acid as the chain transfer agent, the grafting of poly(hydroxyethyl methacrylate) (PHEMA) containing Thy (P(HEMA-Thy)) on CS is possible. The brush-like P(HEMA-Thy) leads Thy moieties to be in sequences. The Thy sequences perform as poly[T] for the specific interaction with ssDNA. The synergistic effect of CS and Thy sequences, i.e., electrostatic and base pairing interactions, results in an effective and efficient binding with ssDNA as well as significant delivery, especially in cellular uptake and cell viability. The use of CS in combination with Thy sequences in brush-like structures on CS is a model for other polysaccharides to be conjugated with the as-designed nucleic acid sequences for potential gene delivery.

Determination of pepsin by capillary electrophoresis using mixed polymer coated capillary with switchable properties toward protein adsorption/desorption.

In this work, a simple online preconcentration method for quantitative detection of pepsin was realized by using the binary mixed polymer brushes coated capillary with switchable properties toward protein adsorption. Firstly, the binary mixed polymer brushes were prepared by grafting poly(2-methyl-2-oxazoline) and poly(4-vinylpyridine) onto the inner wall of the capillary through a polydopamine anchor. Then the coatings were characterized by X-ray photoelectron spectrometer and electroosmotic flow measurement. The results indicated that the composition of coating could be controlled by varying the feed ratio of poly(2-methyl-2-oxazoline) to poly(4-vinylpyridine) and the inner surface charge could be tuned toward the change of pH and ionic strength. The results showed that when the poly(2-methyl-2-oxazoline)/poly(4-vinylpyridine) mass ratio was 80/20, the highest online preconcentration effect was obtained and the sensitivity enhancement factor was 6.3. Moreover, satisfactory sensitivity (limit of detection: 7.5ng/mL) and good repeatability were obtained with the online preconcentration method. The polymer-coated capillary was still stable for online preconcentration and detection of pepsin after 50 consecutive runs. Last, the proposed method was used successfully to online preconcentrate pepsin in the saliva matrix.

Teflon graft poly N–N-dimethylacrylamide as a ciprofloxacin release system

This work presents the modification of Teflon films, formally named polytetrafluoroethylene, with dimethylacrylamide (DMA) through a graft copolymerization reaction initiated by gamma radiation (from Co-60) to endow the material with the capability to deliver hydrophilic drugs. Results suggest the surface of the grafted films is suitable for the load/release of ciprofloxacin, a broad-spectrum antibiotic, achieving the goal of the study. The analysis was supported by water sessile drop contact angles and swelling in water and phosphate buffers. Characterization of grafted films was completed by attenuated total reflectance infrared spectroscopy (FTIR-ATR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).

Atomic force microscopy characterization of polyethylene terephthalate grafting with poly(styrene sulfonate)

Polyethylene terephthalate (PET) is widely used to elaborate biomaterials and medical devices in particular for long-term implant applications but tuning their surface properties remains challenging. We investigate surface functionalization by grafting poly(sodium 4-styrene sulfonate, PNaSS) with the aim of enhancing protein adhesion and cellular activity. Elucidating the topography and molecular level organization of the modified surfaces is important for understanding and predicting biological activity. In this work, we explore several grafting methods including thermal grafting, thermal grafting in the presence of Mohr’s salt, and UV activation. We characterize the different surfaces obtained using atomic force microscopy (AFM), contact angle (CA), and x-ray photoelectron spectroscopy (XPS). We observe an increase in the percentage of sulfur atoms (XPS) that correlates with changes in (CA), and we identify by AFM characteristic features, which we interpret as patches of polymers on the PET surfaces. This work demonstrates tuning of biomaterials surface by functionalization and illustrates the capability of AFM to provide insights into the spatial organization of the grafted polymer.

Co‐Aggregation Induced by Amphiphilic Membrane Interface for the Capture of Trace Endocrine Disruptors from Water

AbstractEndocrine disruptors (EDCs) are widely detected in water resources owing to the abuse of plastic products, posing a serious global concern. Unfortunately, the rapid, effective, and economical removal of trace EDCs from water remains a significant challenge. Herein, a novel adsorptive membrane (PVPM) with excellent recyclability and stability is prepared by the UV‐initiated grafting of poly(N‐vinylpyrrolidone) (PNVP) onto the surface of polypropylene fibrous membrane (PPM). The PVPM exhibits high flux, low‐pressure drop, and excellent adsorption performance. It can efficiently capture trace (10 µg L−1) EDCs with a removal efficiency of 99%. Notably, the adsorption performance of the PVPM remains unchanged even in river water. A mechanism for the adsorption is proposed based on adsorption kinetics and thermodynamics. Specifically, dynamic hydrophobic microdomains are generated between amphiphilic PNVP and EDCs and form co‐aggregates on the PPM substrate. This co‐aggregation is responsible for the large adsorption capacity for EDCs. A large decrease in the free energy (−16.65 kJ mol−1) of the adsorption process provides additional evidence for the strong adsorption affinity of the PVPM to EDCs. This study introduces a new pathway for designing low‐cost and high‐performance membrane adsorbents for prompt and efficient capture of trace EDCs from water.

Poly(sodium 4-styrenesulfonate) brushes-functionalized UiO-66-NH2 metal-organic framework for high and selective adsorption of dyes

Advanced adsorbents with high adsorption capacity and adsorption selectivity are desirable. Here, a Zr-based metal-organic framework (MOF), UiO-66-NH2 @poly(sodium 4-styrenesulfonate, Nass), was synthesized using the high surface area of MOFs as a substrate and the high grafting density of surface initiated-atom transfer radical polymerization (SI-ATRP). UiO-66-NH2 @poly(Nass) was used to adsorb different dyes. The maximum adsorption capacity (Qm) of methylene blue (MB) and basic fuchsine (BF) was 299.8 and 789.2 mg·g−1, respectively, which were higher than those of Sudan I (SD I, 6.340 mg·g−1), neutral red (NR, 188.1 mg·g−1), methyl orange (MO, 199.5 mg·g−1), and acid chrome blue K (AK, 122.3 mg·g−1). The adsorption isotherms and kinetics were investigated, and it was confirmed that the Langmuir isotherm and the pseudosecond-order kinetic model fit our adsorbents. In the binary mixed solution, the removal rate (R) of MB reached 64.44%, while that of MO was only 3.340% for MB/MO. R was 64.29% for MB and 21.97% for AK for MB/AK and 97.45% for BF and 30.03% for MO for BF/MO, verifying the preferential selectivity to adsorb basic dyes. The superior adsorption was ascribed to multiple interactions, including electrostatic interaction, hydrogen bonding, and π–π accumulation. In addition, the effect of grafting poly(Nass) on the pore size of UiO-66-NH2 was studied. The excellent stability showed that the R dropped by less than 15.62% after five consecutive cycles. The UiO-66-NH2 @poly(Nass) was applied in the determination of MB and BF in water, crucian carp, and green shrimp. Good linearity was observed for MB (R2 = 0.9971) and BF (R2 = 0.9993) in the range of 0.2–30 and 0.5–50 μg·mL-1, respectively, with satisfactory recoveries (in the range of 87.45–101.3% for MB and 90.34–98.86% for BF), achieving favorable practicability.

Surface modification of human hair by grafting poly(methyl methacrylate)

Surface modification of human hair by grafting poly(methyl methacrylate)

Mechanistic Insights of a Thermoresponsive Interface for Fouling Control of Thin-Film Composite Nanofiltration Membranes.

In spite of extensive research, fouling is still the main challenge for nanofiltration membranes, generating an extra transport resistance and requiring a larger operational pressure in practical applications. We fabricated a highly antifouling nanofiltration membrane by grafting poly(N-isopropylacrylamide) (PNIPAM) chains on a bromine-containing polyamide layer. The resulting membrane was found to have a double permeance compared to the pristine membrane, while the rejection of multivalent ions remained the same. In addition, PNIPAM chains yielded a better deposition resistance and adhesion resistance, thereby mitigating the increase of fouling and promoting the recovery of flux during the filtration and traditional cleaning stages, respectively. Moreover, PNIPAM chains shrank when the water temperature was above the lower critical solution temperature (LCST), indicating the formation of a buffer layer between the membrane and pollutants. The buffer layer would eliminate the membrane-foulant interaction energy, thus further enhancing the detachment of pollutants. This simple and efficient cleaning method could act as an enhanced cleaning procedure to remove irreversible fouling. This provides new insights into the fabrication of enhanced antifouling membranes using smart responsive polymer chains.

Proton donor/acceptor copolymer brushes on sulfonated poly(ether ether ketone) membrane: An approach to construct efficient proton transfer pathway in polymer electrolyte membrane fuel cell

Proton transfer in polymer electrolyte membrane is an essential mechanism in polymer electrolyte membrane fuel cell (PEMFC). The development of PEM mostly relies on polymer modification with proton conductive species followed by membrane casting. This brings in the random existence of conductive species in the membrane to result in a limit of conductivity. The present work proposes an alignment of conductive species, i.e., proton donor and acceptor polymer chains, on the membrane through the surface-initiated polymerization so that the proton transfer proceeds effectively and continuously. The grafting of poly(acrylic acid) (Poly(AA) and/or poly(benzimidazole acrylamide) (Poly(BImAm)) onto sulfonated poly(ether ether ketone) membrane (SPEEK) enables the polymer brush decoration on the SPEEK surface. Among various types of copolymer architecture, the statistical copolymer, i.e. SPEEK-Poly(AA63-stat-BImAm26), shows the most significant proton conductivity. The present work demonstrates a simple approach to modify the surface of PEMFC membrane with proton donor/acceptor for proton conductivity enhancement.

Synthesis of chitosan graft poly (acrylic acid-co-2-acrylamide-2-methylpropanesulfonic acid)/graphite oxide composite hydrogel and the study of its adsorption

Chitosan graft poly (acrylic acid-co-2-acrylamide-2-methylpropanesulfonic acid)/graphite oxide (CTS-g-P(AA-co-AMPS)/GO) composite hydrogel is synthesized and used to remove rhodamine 6G (R6G) and methyl violet (MV) from aqueous solutions by adsorption. The composite is characterized by infrared spectroscopy (IR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The effect of the adsorption conditions, including the amount of graphite oxide (GO), the initial concentration of dye solutions, the adsorption time, ionic strength, and the mass of the composite, on the adsorption capacities has been studied in detail. It can be seen that small amount of GO can improve the adsorption capacities of both dyes. It is found that the adsorption capacities of R6G and MV can be increased by 57.26% and 26.39%, respectively, compared with CTS-g-P(AA-co-AMPS graft copolymer. The maximal adsorption capacity of R6G and MV is 625.3 and 326.4 mg/g, respectively. The interaction between GO and dye molecules are speculated. GO acts as crosslinking points and combine with the CTS-g-P(AA-co-AMPS) graft copolymer through hydrogen bonds and electrostatic actions. The adsorption isotherms and thermodynamics are discussed. The Gibbs free energy of R6G and MV is that △GR6GӨ = −2.478 KJ/mol and △GMVӨ = −2.577 KJ/mol and it indicates that the adsorption of R6G and MV on CTS-g-P(AA-co-AMPS)/GO is spontaneous and satisfied the Redlich-Peterson equation. Kinetic studies show that the adsorption is in accordance with the Lagergren pseudo first-order kinetic model.

Synthesis of novel diol modified chitosan and their enhanced selective adsorption behavior for germanium(Ⅳ)

Germanium (Ge) is an important semiconductor material, and its effective extraction and recovery is turning into progressively vital. However, high efficient recovery of Ge(IV) via convenient approach is remaining a challenge. Herein, an efficient adsorbent (HEMA-IDOI-CS) was prepared for recovering of Ge(IV) by grafting poly(hydroxyethyl methacrylate) (HEMA) and 3-chloro-1,2-propanediol onto chitosan (CS). The steric effect of the o-hydroxyl groups is highly desirable to selectively chelate with tetrahedral Ge(IV), which greatly enhanced the efficiency of the CS-based materials. HEMA-IDOI-CS exhibited excellent adsorption performance at pH 3–8. The maximum capacity was 73.91 mg g−1 at pH 4, and the efficiency reached 99.26% at pH 4–6. In addition, HEMA-IDOI-CS exhibited good selectivity for Ge(Ⅳ) in the presence of Zn(II), Cu(II), Mn(II), Pb(II), As(III) and Fe(III). The kinetic data was well fitted with the pseudo-second-order kinetic model and the adsorption behavior is consistent with the Langmuir adsorption isotherm model. Moreover, the recovery rate of the adsorbent preserved 95% after four adsorption-elution cycles, demonstrating its good reusability. The adsorption performance of HEMA-IDOI-CS for Ge(Ⅳ) is much better than that of a lot other adsorbents previously reported.

Bioinspired Catechol-Grafting PEDOT Cathode for an All-Polymer Aqueous Proton Battery with High Voltage and Outstanding Rate Capacity.

Aqueous all‐polymer proton batteries (APPBs) consisting of redox‐active polymer electrodes are considered safe and clean renewable energy storage sources. However, there remain formidable challenges for APPBs to withstand a high current rate while maximizing high cell output voltage within a narrow electrochemical window of aqueous electrolytes. Here, a capacitive‐type polymer cathode material is designed by grafting poly(3,4‐ethylenedioxythiophene) (PEDOT) with bioinspired redox‐active catechol pendants, which delivers high redox potential (0.60 V vs Ag/AgCl) and remarkable rate capability. The pseudocapacitive‑dominated proton storage mechanism illustrated by the density functional theory (DFT) calculation and electrochemical kinetics analysis is favorable for delivering fast charge/discharge rates. Coupled with a diffusion‐type anthraquinone‐based polymer anode, the APPB offers a high cell voltage of 0.72 V, outstanding rate capability (64.8% capacity retention from 0.5 to 25 A g−1), and cycling stability (80% capacity retention over 1000 cycles at 2 A g−1), which is superior to the state‐of‐the‐art all‐organic proton batteries. This strategy and insight provided by DFT and ex situ characterizations offer a new perspective on the delicate design of polymer electrode patterns for high‐performance APPBs.

Synthesis, characterization, and molecular docking analysis of Chitosan-gr-Polysulphanilic acid as antimicrobial water-soluble polymers

As a hydrophilic polysaccharide derived from chitin, chitosan has a broad antibacterial spectrum against bacteria and fungi. Activity depends on polymer molecular weight (MW) and degree of acetylation (DA). The activity of polysulphanilic acid as an antimicrobial is very poor. Chitosan graft polysulphanilic acid was synthesized and characterized by some instrumental tools, such as UV-visible, IR spectroscopy, SEM, XRD, and TGA. The obtained graft was introduced to use as an antimicrobial. The obtained data reveals a good antimicrobial activity for different types of the organism as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. For the effect of chitosan, three antibacterial mechanisms are proposed. The ionic surface interaction results in wall cell leakage the inhibition of the mRNA and protein synthesis via the penetration of chitosan into the nuclei of the microorganisms; and the formation of an external barrier, chelating metals, and provoking the suppression of essential nutrients to microbial growth. It is likely that all events occur simultaneously but at different intensities. Chitosan–graft–polysulphanilic acid as a water-soluble polymeric material gives higher efficiency than chitosan and the used references for both gram-positive and gram-negative bacteria. Also, The molecular docking analysis showed that Chitosan-gr-Polysulphanilic acid interacts with the five receptors via different types of interactions, such as hydrogen bonding, van der Waals, and pi-interactions with high binding energies. Also, Chitosan–graft–poly sulphanilic acid has better ADMET and physicochemical properties. So, Chitosan–graft–poly sulphanilic acid can be used as an antimicrobial agent.

Hollow polypyrrole coated with mesoporous silica nanoparticles graft copolymer multifunctional nanocomposites for intracellular cancer therapy

A novel hollow polypyrrole coated by mesoporous silica nanoparticles graft poly(2-(4-formylbenzoyloxy)ethyl methacrylate- co -2-(dimethylamino)ethyl methacrylate)- block -poly(triethylene glycol methyl ether methacrylate) multifunctional nanocomposite (HPPy@MSN-SS-NH- g -P(FBEMA- co -DMAEMA)- b -PTEGMA) was designed and prepared via disulfide bond linkages. This material as a gatekeeper integrated multifunctionality such as pore capping, and pH and potothermal multistimuli response abilities, and possessed good photothermal stability, near-infrared (NIR) photothermal conversion capacity and dispersion stability in aqueous solution. It could entrap anticancer doxorubicin (DOX) by pore channels of HPPy@MSN, the core of amphiphilic copolymer micelles and Schiff base linkages, offering a load capacity and load efficiency of up to about 41.5 and 83.1%, respectively. Dynamic light scattering analysis showed that the DOX-loaded preparations had particle size of less than 300 nm, and could achieve intracellular chemo–photothermal combination therapy by controlling the mesopore on-off based on the gatekeepers, tumor environments including pH and reductant stimuli. The drug-loaded nanoparticles exhibited optimal drug release dynamics in cancer tissues upon triggered by pH and glutathione (GSH) under the NIR irradiation. Cell counting Kit-8 assay manifested that the nanocarriers are non-toxic and safe, whereas the drug-loaded preparations exhibited robust anticancer efficacy. Cellular uptake and TUNEL assay revealed high concentrations of DOX accumulating around and inside Hela cells, accordingly producing significant tumor cell apoptosis. Therefore, the newly-developed materials can be used for comprehensive therapy of cancer as a promising candidate of drug delivered carriers. • We prepared hollow PPy coated with MSNs graft copolymer multifunctional composites. • The nanocomposites exhibited pH, reductant and potothermal multi-responsivities. • This material entrapped DOX by pores, hydrophobic actions and Schiff base linkages. • The drug release was triggered by synergism of pore capping, pH, reductant and NIR. • A chemo–photothermal combination therapy could be achieved by the mesopore on-off.

Surface-initiated atom-transfer radical polymerization (SI-ATRP) of bactericidal polymer brushes on poly(lactic acid) surfaces

We have modified the surface of poly(lactic acid) (PLA) by bromination in the presence of N-bromosuccinimide (NBS) under UV irradiation. This new approach to impart functionality to the surface does not effect the bulk of the material. Brominated PLA surfaces served as initiators for atom-transfer radical polymerization (SI-ATRP) of 2-(methacryloyloxy)ethyl]trimethylammonium chloride, a quaternary ammonium methacrylate (QMA). Grafting of poly(QMA) brushes rendered PLA films hydrophilic and these films displayed a three-order of magnitude increase in antimicrobial efficacy against Gram-negative bacteria such as Escherichia coli as compared to unmodified PLA. The two-step strategy described here to modify PLA surface represents a useful route to modified PLA materials for biomedical and antimicrobial packaging applications.