Farha Masood

Polymeric nanoparticles for targeted drug delivery system for cancer therapy.

A targeted delivery system based on the polymeric nanoparticles as a drug carrier represents a marvelous avenue for cancer therapy. The pivotal characteristics of this system include biodegradability, biocompatibility, non-toxicity, prolonged circulation and a wide payload spectrum of a therapeutic agent. Other outstanding features are their distinctive size and shape properties for tissue penetration via an active and passive targeting, specific cellular/subcellular trafficking pathways and facile control of cargo release by sophisticated material engineering. In this review, the current implications of encapsulation of anticancer agents within polyhydroxyalkanoates, poly-(lactic-co-glycolic acid) and cyclodextrin based nanoparticles to precisely target the tumor site, i.e., cell, tissue and organ are highlighted. Furthermore, the promising perspectives in this emerging field are discussed.

Encapsulation of Ellipticine in poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) based nanoparticles and its in vitro application.

Biodegradable, biocompatible, renewable and non-toxic polyhydroxyalkanoates (PHAs) based nanoparticles are the novel nanotherapeutic tool which are used for the encapsulation of antineoplastic drugs for cancer therapy. In this study, poly-3-hydroxybutyrate-co-5 mol% 3-hydroxyvalerate (PHBV-S), poly-3-hydroxybutyrate-co-11 mol% 3-hydroxyvalerate (PHBV-11) and poly-3-hydroxybutyrate-co-15 mol% 3-hydroxyvalerate (PHBV-15) were used as a nanocarrier for encapsulation of Ellipticine (EPT). EPT is a model anticancer drug. Physicochemical characteristics such as particle size, its morphology and zeta potential of blank and EPT loaded PHBV-S, PHBV-11 and PHBV-15 nanoparticles were studied. In vitro cytotoxicity tests confirmed that the blank PHBV-S, PHBV-11 and PHBV-15 nanoparticles were demonstrating significant biocompatibility without affecting the survival of cancer cell line A549. The loading efficiency of EPT in PHBV nanoparticles was observed in the range of 39.32 to 45.65%. The % inhibition of cancer cell line A549 ranged from 64.28 to 67.77% in comparison to EPT alone in which % inhibition found to be ≤45.11%. The IC50 value for each of three different formulations of EPT loaded PHBV nanoparticles ranged from 1.00 to 1.31 μg/mL. The order of % inhibition of cancer cell line A549 for drug loaded nanoparticles was EPT-PHBV-15>EPT-PHBV-S>EPT-PHBV-11. This system had demonstrated a great potential to increase the cytotoxic effect of EPT by increasing its bioavailability.

Polyhydroxyalkanoates – what are the uses? Current challenges and perspectives

Abstract Over the past few decades, a considerable attention has been focused on the microbial polyhydroxyalkanoates (PHAs) owing to its multifaceted properties, i.e. biodegradability, biocompatibility, non-toxicity and thermo-plasticity. This article presents a critical review of the foregoing research, current trends and future perspectives on the value added applications of PHAs in the biomedical, environmental and industrial domains of life.

Characterization of physical and biodegradation properties of poly-3-hydroxybutyrate-co-3-hydroxyvalerate/sepiolite nanocomposites

The pristine sepiolite was treated with the 3-aminopropyl triethoxy silane (APTES). The APTES grafted sepiolite (APTES-G-SP) was used to develop the poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV)/sepiolite nanocomposite films by the solution-casting method. Scanning electron micrographs showed that the APTES-G-SP fibers were well embedded in the polymer matrix. Fourier transform Infrared spectroscopy attributed the formation of covalent bonds between the APTES-G-SP and PHBV in the nanocomposite film. Thermal and water-barrier properties of the nanocomposite films were significantly improved. Biodegradation studies indicated the conversion of the crystalline structure of the nanocomposite films into the amorphous one as a result of the synergistic effect of the abiotic and biotic degradation processes. The results of this study provide sound evidence about the use of the biodegradable nanocomposite films with the better thermal and water barrier properties for the food packaging industry.

Is atomic rearrangement of type IV PHA synthases responsible for increased PHA production

Background: Type IV PHA synthase is a key enzyme responsible for catalyzing the formation of non-toxic, biocompatible, and biodegradable short-chain-length polyhydroxyalkanoates (scl-PHA) under the growth-limiting conditions in the members of the genus Bacillus. Results: The comparative in vitro and in silico analysis of the phaC subunit of type IV PHA synthases among Bacillus cereus FA11, B. cereus FC11, and B. cereus FS1 was done in our study to determine its structural and functional properties. Conserved domain analysis demonstrated that phaC subunit belongs to the alpha/beta (α/β) hydrolase fold. The catalytic triad comprising of cysteine (Cys), histidine (His), and aspartate (Asp) was found to be present at the active site. A shorter inter-atomic distance was found between the carboxyl (–COO) group of Asp and amino (NH2) group of His. Furthermore, slightly long inter-atomic distances between sulfhydryl (SH) group of Cys and NH2 group of His may be pointing toward the broader substrate specificity of type IV PHA synthases. However, a shorter distance between the SH group of Cys and NH2 group of His in case of B. cereus FC11 leads to a higher enzymatic activity and maximum PHA yield (49.26%). Conclusion: The in silico study verifies that the close proximity between SH group of Cys and NH2 group of His in phaC subunit of type IV PHA synthases can be crucial for synthesis of scl-PHA. However, the catalytic activity of type IV PHA synthases declines as the distance between the sulfur (S) atom of the SH group of Cys and the nitrogen (N) atom of NH2 group of His increases.

Characterization and application of roxithromycin loaded cyclodextrin based nanoparticles for treatment of multidrug resistant bacteria.

An outbreak of infections with a high mortality rate caused by multidrug resistant (MDR) bacteria is one of the biggest health challenges globally. A class IV drug, roxithromycin (ROX), has poor solubility. In this study, ROX was first encapsulated in the cavity of each of the β-cyclodextrin (βCD) and hydroxypropyl-β-cyclodextrin (HPβCD). Then, each of the resulting βCD-ROX inclusion complex and HPβCD-ROX inclusion complex were separately loaded into poly-(lactic-co-glycolic acid) (PLGA) to synthesize βCD-ROX/PLGA and HPβCD-ROX/PLGA nanoparticles (NPs). Blank and ROX loaded PLGA (ROX-PLGA) NPs were also prepared. The loading efficiency of ROX is comparatively high for HPβCD-ROX/PLGA NPs in comparison to the βCD-ROX/PLGA NPs and ROX-PLGA NPs. All designed formulations showed significant (P<0.0001) antibacterial activity against the selected MDR bacterial strains. In a nutshell, this study demonstrated a great therapeutic potential of the above-mentioned delivery systems for treatment of MDR bacteria.

Polyhydroxyalkanoates in the Food Packaging Industry

Abstract Bioplastics such as polyhydroxyalkanoates (PHAs) are considered an ideal candidate for food packaging applications. The promising features of PHAs include biodegradability, hydrophobicity, nontoxicity, nonlinear optical activity, thermoplasticity, piezoelectricity, and impermeability to gases and/or water. In this chapter, the “Introduction” section focuses on the basic characteristics and the biosynthesis of PHAs. The previous research and recent developments in the commercial growth of PHAs are highlighted. This is followed by a detailed outline of the physical properties of PHAs, i.e., thermal properties, crystallinity, mechanical properties, permeability, migration, and degradability. Furthermore, we consolidate the present information on the applications of PHAs in blends/composites, nanocomposites, multilayer films, paper coating, and active food packaging. Finally, some examples of commercial uses of PHAs in the food packaging industry are discussed. The chapter concludes with a summary as well as promising future prospects.