pH-sensitive Poly Research Articles

Smart membranes with pH-responsive control of macromolecule permeability

Utilization of membranes for separation of macromolecules has gained wide interest in the last decade, especially after the development of smart membranes with tunable properties for improved separation performance. In this work, we fabricated hybrid membranes with variable pore sizes that depend on the pH of the environment. Hybrid membranes were prepared by conformally coating the pore walls of anodic aluminum oxide (AAO) templates with the pH sensitive poly(methylacrylic acid-co-ethylene glycol dimethacrylate) (p(MAA-co-EGDMA)) polymer using initiated chemical vapor deposition (iCVD). Performance of the membranes was investigated under different pH conditions using nanoparticles, polyacrylic acid (PAA) and BSA protein as permeates. Reduced pore sizes at pH 9 due to swollen polymer decreased the permeability of permeates compared to that at pH 3. In addition to size, charge interactions between the polymer surface and permeates affected the permeation. At high pH values, permeation of BSA was reduced due to reduced pore size and the electrostatic interactions with the polymer.

Modeling of drug release behavior of pH and temperature sensitive poly(NIPAAm-co-AAc) IPN hydrogels using response surface methodology and artificial neural networks

An interpenetrated polymer network (IPN) poly(NIPAAm-co-AAc) hydrogel was synthesized by two polymerization method: emulsion and solution polymerization. The pH- and temperature-sensitive hydrogel was loaded by swelling with riboflavin drug, a B2 vitamin. The release of riboflavin as a function of time has been achieved under different pH and temperature environments. The determination of experimental conditions and the analysis of drug delivery results were achieved using response surface methodology (RSM). In this work, artificial neural networks (ANNs) in MATLAB were also used to model the release data. The predictions from the ANN model, which associated input variables, produced results showing good agreement with experimental data compared to the RSM results.

Tetra-Sensitive Graft Copolymer Gels as Active Material of Chemomechanical Valves.

Stimuli-responsive hydrogels combine sensor and actuator properties by converting an environmental stimulus into mechanical work. Those materials are highly interesting for applications as a chemomechanical valve in microsystem technologies. However, studies about key characteristics of hydrogels for this application are comparatively rare, and further research is needed to emphasize their real potential. The first part of this study depicts the synthesis of grafted hydrogels based on a poly(N-isopropylacrylamide) backbone and pH-sensitive poly(acrylic acid) graft chains. The chosen approach of grafted hydrogels provides the preparation of multiresponsive hydrogels, which retain temperature sensitivity besides being pH-responsive. A pronounced salt and solvent response is additionally achieved. Key characteristics for an application as a chemomechanical valve of the graft hydrogels are revealed: (1) independently addressable response to all stimuli, (2) significant volume change, (3) sharp transition, (4) reversible swelling-shrinking behavior, and (5) accelerated response time. To prove the concept of multiresponsive hydrogels for flow control, a net-poly(N-acrylamide)-g-poly(acrylic acid) hydrogel containing 0.6 mol % poly(acrylic acid)-vinyl is employed as active material for chemomechanical valves. Remarkably, the chemomechanical valve can be opened and closed in a fluidic platform with four different stimuli.

PH-Triggered Drug Release of Monodispersed P(St-co-DMAEMA) Nanoparticles: Effects of Swelling, Polymer Chain Flexibility and Drug-Polymer Interactions

Monodispersed pH-sensitive poly(styrene-co-N,N′-dimethylaminoethyl methacrylate) (P(St-co- DMAEMA)) nanoparticles (NPs) were synthesized by emulsion polymerization for use in potential applications in targeted drug delivery to the tumor microenvironment. pH-Sensitive volume swelling and drug release of the NPs with varied St/DMAEMA molar ratios, crosslinking degrees and model drug coumarin-6 loading were explored in vitro to elucidate the pH-sensitive drug release mechanisms. The swelling of the NPs, which accounts for the electrostatic repulsion of protonated tertiary amine groups under acidic conditions, reaches maximum at low pH, low crosslinking density and high DMAEMA content. The NPs undergo a pH-triggered drug release, and under the condition of pH 5 and pH 2, the average release rate during 24 h is 1.5-fold and 3-fold higher than that at physiological pH, respectively. The pH-triggered drug release is related to pH-sensitive swelling, polymer chain flexibility and drug-polymer interaction, and is significantly impacted by the St/DMAEMA molar ratio, degree of crosslinking and drug loading.

Temperature and pH-sensitive injectable hydrogels based on poly(sulfamethazine carbonate urethane) for sustained delivery of cationic proteins

In recent years, protein therapeutics plays a promising role in the field of medicine. However, intrinsic properties of proteins, including short plasma half-life and hydrolytic stability in vivo, are severely limits their application. To surmount these issues, we developed an anionic injectable hydrogel based on temperature- and pH-sensitive poly(ethylene glycol)-poly(sulfamethazine carbonate urethane) (PEG-PSMCU) copolymers for the sustained delivery of cationic model protein, lysozyme. The PEG-PSMCU copolymers exhibit pH and temperature-induced sol-to-gel phase transition in aqueous solutions. The mechanical properties of PEG-PSMCU copolymers, such as viscosity, gelation rate, and mechanical strength, were controllably tunable by varying the polymer weight, pH and temperature. An in vitro biocompatibility test indicated that PEG-PSMCU-based copolymers, even at high polymer concentrations (up to 2000 μg/ml), was not toxic to fibroblast cells. The in vivo gel formation was confirmed by subcutaneous injection of PEG-PSMCU-based copolymer solutions (20 wt%) into Sprague-Dawley (SD) rats, which indicated in situ gel formation with uniform porous structure. Furthermore, an in vivo biodegradation study of the PEG-PSMCU anionic hydrogels showed a surface-controlled degradation of the gel matrix. Lysozyme, chosen as a cationic model protein, was loaded into an anionic hydrogel through ionic and hydrophobic interactions. Lysozyme-loaded PEG-PSMCU copolymers readily formed an in situ hydrogel after subcutaneous injection in SD rats, which markedly retarded the initial burst and led to the sustained release of lysozyme for 7 days. Overall, injectable anionic hydrogels prepared in this study can act as a localized hydrogel depot of cationic proteins, which inhibited initial burst while facilitating sustained release, and open a new paradigm for sustained delivery of cationic proteins.

Self-healing pH-sensitive poly[(methyl vinyl ether)-alt-(maleic acid)]-based supramolecular hydrogels formed by inclusion complexation between cyclodextrin and adamantane

Self-healing materials are of interest for drug delivery, cell and gene therapy, tissue engineering, and other biomedical applications. In this work, on the base of biocompatible polymer poly(methyl vinyl ether-alt-maleic acid) (P(MVE-alt-MA)), host polymer β-cyclodextrin-grafted P(MVE-alt-MA) (P(MVE-alt-MA)-g-β-CD) and guest polymer adamantane-grafted P(MVE-alt-MA) (P(MVE-alt-MA)-g-Ad) were first prepared. Then through taking advantage of the traditional host-guest interaction of β-cyclodextrin and adamantane, a novel self-healing pH-sensitive physical P(MVE-alt-MA)-g-β-CD/P(MVE-alt-MA)-g-Ad supramolecular hydrogels were obtained after simply mixing the aqueous solution of host polymer and guest polymer. This kind of supramolecular hydrogels not only possess pH-sensitivity, but also possess the ability to repair themselves after being damaged.

Temperature- and pH-dependent aggregation behavior of hydrophilic dual-sensitive poly(2-oxazoline)s block copolymers as latent amphiphilic macromolecules

A variety of hydrophilic diblock and triblock copolymers of AB and ABA type with temperature-sensitive poly(2-isopropyl-2-oxazoline) blocks und pH-sensitive poly(2-carboxyethyl-2-oxazoline) blocks have been synthesized. The temperature- and pH-induced reversible phase transition renders the block copolymers as amphiphilic macromolecules and allows for defined aggregation through self-assembly following the packing parameter of amphiphilic macromolecules. Size, structure and arrangement of the individual block copolymer segments define the temperature and pH values of the transitions as well as the nature of the formed aggregates. DLS measurements were used to determine the transition temperatures at selected pH values in aqueous solution whereas AFM was used to visualize and characterize the formed aggregates adsorbed on Si wafer surfaces. In the case of vesicles formed by the diblock and triblock copolymers, double and monolayer membranes could be verified. The tendency of different states of organization of poly(2-isopropyl-2-oxazoline) blocks from crystalline to amorphous is assumed to be the cause for the different box-like structures determined on Si wafer surfaces.

Synthesis of dual stimuli-responsive amphiphilic particles through controlled semi-batch emulsion polymerization

The synthesis and property of dual stimuli-responsive amphiphilic particle consisting of a hydrophobic component, a pH-sensitive poly(ethyleneimine) (PEI) and a temperature-sensitive poly(N-isopropyl acrylamide) (PNIPAm) have been investigated. This novel type of multicomponent polymer (MCP) particles were prepared through a one-pot controlled semi-batch emulsion polymerization which involved an initial formation of PNIPAm/PEI core-shell nanogel particle via a graft copolymerization of N-isopropyl acrylamide from PEI, followed by the seeded emulsion polymerization of methyl methacrylate or styrene. Properties of these MCP particles including particle composition, size, size distribution, surface charge and morphology were systematically examined. The structure of hydrophobic monomer was found to strongly influence the morphology of resultant MCP particles. The multilayered polystyrene/PNIPAm/PEI particles exhibited unique property of temperature-tunable surface charge. This property was demonstrated through studies of intracellular uptake of FITC-label PS/PNIPAm/PEI nanoparticles into HeLa cells at 27 and 37 °C. The results provide some insights into the design of future stimulus-responsive nanoparticle-based therapeutics.

PH-Sensitive Vesicles Formed by Amphiphilic Grafted Copolymers with Tunable Membrane Permeability for Drug Loading/Release: A Multiscale Simulation Study

By synergizing molecular dynamics and dissipative particle dynamics simulations, we investigate the assembly of amphiphilic grafted copolymers into vesicles and the loading/release of doxorubicin hydrochloride (DOX·HCl). The copolymers, PAE-g-PEGLA, comprise pH-sensitive poly(β-amino ester) grafted with hydrophilic poly(ethylene glycol) and hydrophobic poly(d,l-lactide). The vesicle formation is revealed to follow an aggregation–rearrangement mechanism, in which small clusters first form, then rearrange, and finally merge into bilayer-structured vesicles. The vesicle interior size and membrane thickness are substantially affected by the exchange quantity and frequency between tetrahydrofuran and water. At pH = 7, DOX·HCl is loaded into the vesicle interior, and the loading efficiency increases with increasing polymer concentration. At pH < 7, PAE blocks are protonated and hydrophilic, which causes the structure transition of membrane thus tuning membrane permeability for DOX·HCl release. When PLA blocks b...

Nanoassemblies constructed from bimodal mesoporous silica nanoparticles and surface-coated multilayer pH-responsive polymer for controlled delivery of ibuprofen.

The pH-sensitive poly(D-A) grafted amine-functionalized bimodal mesoporous silica (D-A/BMMs) was prepared by a facile method used as a drug delivery vehicle. They exhibited superior properties such as good dispersion in aqueous medium, high drug loading efficiency, improved stability and high drug release rates. Meanwhile, its structural features and performances in a controlled delivery of ibuprofen (IBU) were systematically investigated by using XRD, N2 adsorption and desorption, SEM, TEM, FT-IR, elemental analysis and TG techniques. The results demonstrated that the obtained nanocomposite presented a flexible control over drug release by controlling the grafting amount of D-A onto the mesopores surface of aminated BMMs. The cumulative percent release of IBU from D-A/BMMs was found to be much higher at pH 7.4 than at pH 2.0. The release rate was very slow in an acidic medium but became faster in a neutral medium, owing to hydrogen bonding in an acidic medium and electrostatic repulsion between negatively charged carboxyl groups in an alkaline medium.

Injectable Hydrogel: Amplifying the pH Sensitivity of a Triblock Copolypeptide by Conjugating the N-Termini via Dynamic Covalent Bonding.

We explore the self-assembly behavior of aqueous solutions of an amphiphilic, pH-sensitive poly(l-alanine)-b-poly(l-glutamic acid)-b-poly(l-alanine), (A5E11A5) triblock copolypeptide, end-capped by benzaldehyde through Schiff base reaction. At elevated concentrations and under physiological pH (7.4) and ionic strength (0.15M), the bare copolypeptide aqueous solutions underwent a sol-gel transition after heating and slow cooling thermal treatment, forming opaque stiff gels due to a hierarchical self-assembly that led to the formation of β-sheet-based twisted super fibers (Popescu et al. Soft Matter 2015, 11, 331-342). The conjugation of the N-termini with benzaldehyde (Bz) through a Schiff base reaction amplifies the copolypeptide pH-sensitivity within a narrow pH window relevant for in vivo applications. Specifically, the dynamic character of the imine bond allowed coupling/decoupling of the Bz upon switching pH. The presence of Bz conjugates to the N-termini of the copolypeptide resulted in enhanced packing of the elementary superfibers into thick and short piles, which inhibited the ability of the system for gelation. However, partial cleavage of Bz upon lowering pH to 6.5 prompted recovery of the hydrogel. The sol-gel transition triggered by pH was reversible, due to the coupling/decoupling of the benzoic-imine dynamic covalent bonding, endowing thus the gelling system with injectability. Undesirably, the gelation temperature window was significantly reduced, which however can be regulated at physiological temperatures by using a suitable mixture of the bare and the Bz-conjugated coplypeptide. This triblock copolypeptide gelator was investigated as a scaffold for the encapsulation of polymersome nanocarriers, loaded with a hydrophilic model drug, calcein. The polymersome/polypeptide complex system showed prolonged probe release in pH 6.5, which is relevant to extracellular tumor environment, rendering the system potentially useful for sustained delivery of anticancer drugs locally in the tumor.

Rheological behavior and reversible swelling of pH sensitive poly(acrylamide-co-itaconic acid) hydrogels

The study involved preparation of poly(acrylamide-co-itaconic acid) hydrogels by radical cross-linking copolymerization. The copolymer hydrogels were characterized through infrared spectroscopy, thermal analysis, swelling measurements and in oscillatory and steady shear rheology. Results showed that more stable copolymers were formed due to the strong interaction in the hydrogels. These hydrogels have shown substantial percent swelling in water and shrinking in saline solution and acidic buffers. The rheological properties were described by the Herschel-Bulkley and power-law models to explore their non-Newtonian behavior. The results showed that higher itaconic acid content raised the polymer viscosity; the degree of shear-thinning and polymer elasticity (G′) were also increased. The transition from the viscous (G′ G″) occurs at a crossover frequency ranged from 17.8 rad/s for polyacrylamide to 15.7, 12.8 and 12.5 rad/s for copolymers.

Design and synthesis of pH-sensitive polymeric micelles for oral delivery of poorly water-soluble drugs

pH-sensitive polymer poly (polylactide-co-methacrylic acid)–b-poly (acrylic acid) was synthesized using atom transfer radical polymerization and ring-opening polymerization and characterized by gel permeation chromatography and 1H NMR. The polymers can self-assemble to form micelles in aqueous medium, which respond rapidly to pH change within the gastrointestinal relevant pH range. Critical micelle concentrations and pH response behavior of the polymeric micelle were investigated. Water-insoluble drug nifedipine was loaded and the drug-loading content can be controlled by tuning the composition of the polymers. The in vitro release studies indicate pH sensitivity enabled rapid drug release at the environment of simulated intestinal fluid (pH 7.36), the cumulative released amount of NFD reached more than 80% within 24 h, while only 35% in the simulated gastric fluid (pH 1.35). All the results showed that the pH-sensitive P(PLAMA-co-MAA)–b-PAA micelle may be a prospective candidate as oral drug delivery carrier for hydrophobic drugs with controlled release behavior.

Grafting of pH-sensitive poly (N,N-dimethylaminoethyl methacrylate-co-2-hydroxyethyl methacrylate) onto HNTS via surface-initiated atom transfer radical polymerization for controllable drug release

ABSTRACTCopolymer brushes composed of N,N-dimethylaminoethyl methacrylate (DMAEMA) and 2-hydroxyethyl methacrylate (HEMA) were tethered on the surface of HNTs (HNTs) through surface-initiated atom transfer radical polymerization (SI-ATRP). ATRP initiator was anchored to surface and copolymers were synthesized from surface with different compositions of monomers. Successful grafting of copolymer brushes was approved by FTIR, TGA, XPS, FE-SEM, TEM, and N2 adsorption-desorption.1H NMR was used to determine the composition of copolymers. pH-sensitive properties of copolymer-grafted nanotubes were investigated by UV-visible absorbance in different pH values. Finally, loading and in vitro drug release from neat and copolymer-grafted HNTs were investigated using diphenhydramine hydrochloride as a model drug. Incorporation of DMAEMA to structure of polymers led to pH sensitivity of grafted-copolymers and controlled release of drug upon varying the pH of release medium. pH-dependent drug release showed that drug release was increased by decreasing pH of release medium and increasing DMAEMA content.

Raspberry-Shaped Independent Temperature and pH Dual-Responsive CPMAA@CPNIPAM Yolk/Shell Microspheres for Site-Specific Targeted Delivery of Anticancer Drugs

Raspberry-shaped CPMAA@CPNIPAM yolk/shell microspheres (RS-CPMAA@CPNIPAM), with independent pH sensitive movable cross-linked poly(methacrylic acid) (CPMAA) cores and temperature responsive cross-linked poly(N-isopropylacrylamide) (CPNIPAM) shells, have been successfully fabricated as a potential drug delivery system (DDS) for the controlled release of anticancer drugs, via the one-pot two-step “self-removing” approach based on the consecutive radical seeded emulsion copolymerization. Their formation mechanism was also proposed and the hydrogen bonds between amide groups (in NIPAM and its oligomers) with carboxyl groups (in CPMAA) should be the determining factor for the different morphology. Compared with the regular CPMAA@CPNIPAM core/shell microspheres, the RS-CPMAA@CPNIPAM yolk/shell microspheres possessed higher drug-loading capacity and better controlled release performance, with Doxorubicin (DOX) as a model anticancer drug. Most importantly, the novel raspberry-shaped yolk/shell microspheres posses...

Novel pH-Sensitive Poly(Vinyl Alcohol) Based Polyampholyte as Pervaporation Membrane

Sodium acrylate (NaAA) and acrylamide (AM) were grafted onto poly (vinyl alcohol) (PVA) using potassium persulfate as an initiator, Graft copolymerization namely poly (vinyl alcohol)-g-poly (acrylamide/sodium acrylate) (PVA-g-PAM/SAC). The poly (vinyl alcohol)-g-poly (vinylamine/sodium acrylate) (PVAMC) was prepraed by Hofmann rearrangement.The PVAMC homogeneous membrane was characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM).The water resistance of the PVAMC membranes is the best when pH of the PVAMC solutions was 4, at that time the numbers of-NH3+ and-COO- groups trended to be equal, so the isoelectric point was pH=4. At 90 °C the pervaporation of PVAMC composite membrane was tested and showed that the separation factor and the permeate flux were about 1001 and 1341 g/(m2·h) for 90wt% ethanol aqueous solution, and they were about 1297 and 1040 g/(m2·h) for 90wt% isopropanol aqueous solution.

Synthesis and in vitro evaluation of pH-sensitive PEG-I-dC16 block polymer micelles for anticancer drug delivery.

To develop an acid trigger release of antitumour drug delivery carriers, pH-sensitive amphiphilic poly (ethyleneglycol)-imine-benzoic-dipalmitate (PEG-I-dC16 ) polymers were designed and synthesized and the drug-loaded micelles were evaluated in vitro. PEG-I-dC16 synthesized by Schiff base synthetic method and characterized by (1) H-NMR. To determine the drug-loading capacity, doxorubicin (DOX) was encapsulated in the micelles using membrane dialysis method. Zeta potential, particle size, drug-loading capacity, in vitro drug release in different pH conditions and cytotoxicity evaluation of micelles were carried out comparing with non-acid liable PEG-amide-benzoic-dipalmitate (PEG-A-dC16) polymers micelles. The cellular uptake and intracellular distribution of DOX were detected by flow cytometry and confocal laser scanning microscope. Drug-loading capacity and encapsulation efficiency of micelle (PEG molecular weight 2k) were 12.7 ± 1.1% and 49.8 ± 2.2%, respectively. The average particle size was 72.3 ± 2.5 nm. The DOX release rate of PEG-I-dC16 micelles is much higher at pH 6.5 than at pH 7.4. DOX cellular uptake and nuclear accumulation of PEG-I-dC16 micelles were more efficiency than that of PEG-A-dC16 micelles. The pH-sensitive PEG-I-dC16 micelles could be a promising drug delivery system for anticancer drugs.

Impact of hydrogenation on physicochemical and biomedical properties of pH-sensitive PMAA-b-HTPB-b-PMAA triblock copolymer drug carriers.

pH-Sensitive poly(methacrylic acid)-block-hydroxyl-terminated polybutadiene-block-poly(methacrylic acid) (PMAA-b-HTPB-b-PMAA) was synthesized and then hydrogenated in this work. The chain structure, phase behavior and thermal properties were characterized by(1)H NMR, FTIR, XRD, DSC, TGA, etc., and the physicochemical and biomedical properties were investigated via fluorescence spectroscopy, TEM, DLS, loading and release of drug and MTT, and so on. The experimental results indicated that the hydrogenation led to the change in the chain aggregate structure of hydrophobic HTPB blocks and the formation of more stable spherical core-shell micelle aggregates, and the critical micelle concentration decreased from 41.8 mg L(-1)before hydrogenation to 4.4 mg L(-1)after hydrogenation. The hydrogenated block copolymer micelle aggregates exhibited pH-triggered response, and could entrap twice as much hydrophobic drug as the unhydrided counterparts and the encapsulation efficiency was significantly improved, which makes them fine to meet the requirements for drug carriers. Therefore, the hydrogenated PMAA-b-HTPB-b-PMAA copolymer micelles as drug target release carriers can be well used in the field of prevention and treatment of cancers.

Controlled release behavior of pH-sensitive poly(2-(diethylamino)ethyl methacrylate)/palygorskite composite microspheres prepared via pickering emulsion polymerization

(11.64 mM s) and GON-AN-FA (10.83 mM s) is much larger than that of the traditional positive MRI contrast agents, such as Magnevist (4.7 mM s). The results of cell viability assays indicate that the GON-AN and GON-AN-FA are almost non-cytotoxic. Furthermore, the specificities of GON-AN and GON-AN-FA were evaluated with two kinds of cancer cells that overexpress folate receptor alpha (FRα). The results reinforce that the GON-AN-FA is high-specifically-targetable to cancer cells via recognition of ligand FA and receptor FRα. In addition, the TEM and DLS results indicate that the SPION-AN-FA has a spherical shape, a uniform size and an excellent water-dispersibility (PDI b 0.05). The results of LSCM and flow cytometry demonstrate that the SPION-AN-FA is highly specific to MCF-7 and SPC-A1 cells due to the recognition of ligand FA and receptor FRα. The r1/r2 value of SPION-AN-FA is around 40, which is much higher than that of Resovist® indicating that our SPION-AN-FA has a stronger T2 shortening effect. The T2weighted images of MCF-7 cells incubated with SPION-AN-FA are significantly darker than those of MCF-7 cells incubated with AN, indicating that our SPION-AN-FA has a strong MR imaging efficacy.

Facile Layer-by-Layer Self-Assembly toward Enantiomeric Poly(lactide) Stereocomplex Coated Magnetite Nanocarrier for Highly Tunable Drug Deliveries.

A highly tunable nanoparticle (NP) system with multifunctionalities was developed as drug nanocarrier via a facile layer-by-layer (LbL) stereocomplex (SC) self-assembly of enantiomeric poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) in solution using silica-coated magnetite (Fe3O4@SiO2) as template. The poly(lactide) (PLA) SC coated NPs (Fe3O4@SiO2@-SC) were further endowed with different stimuli-responsiveness by controlling the outermost layer coatings with respective pH-sensitive poly(lactic acid)-poly(2-dimethylaminoethyl methacrylate) (PLA-D) and temperature-sensitive poly(lactic acid)-poly(N-isopropylacrylamide) (PLA-N) diblock copolymers to yield Fe3O4@SiO2@SC-D and Fe3O4@SiO2@SC-N NPs, respectively, while the superparamagnetic properties of Fe3O4 were maintained. TEM images show a clearly resolved core-shell structure with a silica layer and sequential PLA SC co/polymer coating layers in the respective NPs. The well-designed NPs possess a size distribution in a range of 220-270 nm and high magnetization of 70.8-72.1 emu/g [Fe3O4]. More importantly, a drug release study from the as-constructed stimuli-responsive NPs exhibited sustained release profiles and the rates of release can be tuned by variation of external environments. Further cytotoxicity and cell culture studies revealed that PLA SC coated NPs possessed good cell biocompatibility and the doxorubicin (DOX)-loaded NPs showed enhanced drug delivery efficiency toward MCF-7 cancer cells. Together with the strong magnetic sensitivity, the developed hybrid NPs demonstrate a great potential of control over the drug release at a targeted site. The developed coating method can be further optimized to finely tune the nanocarrier size and operating range of pHs and temperatures for in vivo applications.