Poly(styrene-co-maleic acid),partial isobutyl ester

• CAS: 28571-95-1
• Catalog Number: ACM28571951
• Category: Main Products
• Synonyms: POLY(STYRENE-CO-MALEIC ACID), PARTIAL ISOBUTYL ESTER;2-butenedioicacid(z)-,mono(2-methylpropyl)ester,polymerwithethenylbenzen;STYRENE-MALEIC ACID HALF ESTER COPOLYMER;Poly(styrene-co-maleic acid), partial isobutyl ester average Mv ~65,000

Case Study

Poly(styrene-co-maleic acid), Partial Isobutyl Ester for Drug Delivery Micelles

Varshosaz, Jaleh, et al. Iet Nanobiotechnology 12.4 (2018): 466-472.

L-asparaginase (L-ASNase) is a critical therapeutic enzyme for treating acute lymphoblastic leukemia (ALL), the most common childhood cancer. However, its clinical utility is limited by short plasma half-life, immunogenicity, and susceptibility to proteolytic degradation. This study reported a bioconjugation strategy to improve the pharmacokinetic profile and stability of L-ASNase by covalently attaching it to poly(styrene-co-maleic acid) (PSMA) nanoparticles. Conjugation was achieved using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), which activates carboxylic acid groups of the polymer to form stable amide bonds with amine groups of the enzyme.
Experimental Protocol: PSMA nanoparticles were prepared and characterized for particle size and zeta potential. L-ASNase was conjugated to PSMA nanoparticles using EDC/NHS chemistry at optimized polymer-to-enzyme and crosslinker ratios. The conjugation efficiency was determined by measuring protein content. Particle size and zeta potential of the bioconjugates were measured by dynamic light scattering. Enzyme activity was assessed using the Nesslerization method. Stability was evaluated under varying pH conditions and in the presence of proteolytic enzymes. The Michaelis-Menten constant (Km) was determined to assess substrate affinity. Plasma half-life was measured in phosphate buffered saline and in plasma.
Performance Evaluation: The PSMA-conjugated L-ASNase demonstrated significantly enhanced stability against pH changes and proteolysis compared to the native enzyme. The conjugated enzyme exhibited a lower Km value, indicating improved affinity for the substrate. The plasma half-life of the conjugated enzyme was substantially greater than that of the native enzyme in both phosphate buffered saline and plasma. Overall, the PSMA nanoparticle bioconjugate outperformed the alternative polymer conjugate, demonstrating superior enzyme stabilization, prolonged circulation time, and maintained catalytic activity. These results support PSMA as an effective carrier for improving the therapeutic profile of L-ASNase.

Poly(styrene-co-maleic acid), Partial Isobutyl Ester as Dispersant for Nanoparticles

Dalela, Manu, et al. ACS applied materials & interfaces 7.48 (2015): 26530-26548.

Poly(styrene-co-maleic acid)-paclitaxel (PSMAC-PTX) nanoparticles were prepared by conjugating paclitaxel (PTX) to a biocompatible poly(styrene-co-maleic anhydride) copolymer via ester linkage. The amphiphilic conjugate self-assembled into nanoparticles in aqueous media, creating a pH-sensitive delivery system that exploits the Warburg effect in solid tumors. The design aimed to achieve preferential drug release at the lower pH of the tumor microenvironment while maintaining stability at physiological pH, thereby enhancing the therapeutic index of paclitaxel.
Experimental Protocol: Poly(styrene-co-maleic anhydride) was synthesized and characterized, then conjugated with PTX through ester bond formation. The PSMAC-PTX conjugate self-assembled into nanoparticles in aqueous solution. In vitro PTX release was measured at pH 5.5 (tumor-mimetic) and pH 7.4 (physiological) using dialysis. Cytotoxicity was evaluated by MTT assay across multiple cancer cell lines after 72 hours. Cellular uptake was assessed by confocal microscopy, and apoptosis was quantified by flow cytometry.
Performance Evaluation: The PSMAC-PTX nanoparticles exhibited pronounced pH-dependent drug release, with significantly higher PTX release at pH 5.5 compared to pH 7.4. IC50 values ranged from 9.05 to 18.43 ng/mL PTX equivalent across various cancer cell lines. Pharmacokinetic studies revealed that conjugation to PSMAC increased both plasma and tumor maximum concentration of PTX and prolonged its plasma half-life and tumor retention through the enhanced permeability and retention (EPR) effect. In vivo administration produced significant tumor growth inhibition with improved apoptosis in EAT-bearing syngeneic mice compared to the clinical formulation. No subacute toxicity was observed in major organs, tissues, or the hematological system.

Poly(styrene-co-maleic acid), Partial Isobutyl Ester for pH-Responsive Membrane Applications

Liu, Yuanyuan, et al. Macromolecular Chemistry and Physics 215.15 (2014): 1446-1455.

Honeycomb-patterned porous films fabricated via the breath figure (BF) method have attracted considerable interest for applications in sensors, catalysis, membrane separation, and biological interfaces. This work provide a strategy for preparing highly ordered honeycomb-patterned films of poly(ether sulfone) (PES), an engineering plastic with excellent thermal and chemical stability. The key challenge was the limited solubility of PES in common volatile solvents required for the BF process. The researchers overcame this limitation by using a dichloromethane (DCM) suspension of PES as the casting solution, supplemented with an amphiphilic block copolymer additive, poly(styrene-co-maleic acid) partial isobutyl ester (PSME), to stabilize water droplet arrays during solvent evaporation.
Experimental Protocol: PES was dispersed in DCM at various concentrations to form casting suspensions. PSME was added as an amphiphilic stabilizer. Films were cast on glass substrates under controlled humidity from 50% to 95% relative humidity. Film morphologies were characterized by SEM and AFM. Pattern regularity was quantified using Voronoi tessellation analysis. Chemical and thermal stability were tested by immersing films in strong acid (HCl) and base (NaOH) solutions at elevated temperatures for extended periods.
Performance Evaluation: The addition of PSME significantly improved honeycomb pattern regularity by stabilizing condensed water droplets at the solution-air interface during the BF process. A clear synergistic effect between polymer concentration and humidity was observed, with optimal conditions yielding highly ordered hexagonal pore arrays. Quantitative Voronoi analysis confirmed enhanced pattern uniformity. The resultant PES honeycomb films demonstrated exceptional durability, maintaining their porous structure after prolonged exposure to strong acid and base solutions under heating. This stability is attributed to the inherent chemical robustness of the PES matrix, making these films suitable for demanding applications under harsh operating environments.