Starch Acetate Research Articles

Characterization of concanavalin A-conjugated resistant starch acetate bioadhesive film for oral colon-targeting microcapsule delivery system

For the effectiveness of bioactive ingredient targeting delivery in the gastrointestinal tract (GIT), the concanavalin A (Con A)-conjugated RSA film was developed for the potential bioadhesive coating material for colon-targeting bioadhesive microcapsules which were designed by the method of extrusion–spheronization and film coating process. The Con A-conjugated RSA films with coupled Con A from 8 to 32μg/mg showed sufficient higher storage modulus (G′) and glass transition temperature (Tg). The G′ and Tg increased as immersion in simulated digestive fluids progressed which allowed the films transformed from a viscoelastic state to a glassy state and is benefit for the bioactive ingredients releasing. Through adjusting the amount of coupled Con A the brittleness time and brittlement of Con A-conjugated RSA film could be adjusted and controlled for matching the colon targeting and releasing performance. The in-vitro and in-vivo study demonstrated that the Con A-conjugated RSA film coated microcapsules have good colon targeting and bioadhensive properties which could not only target bioactive molecules to the colon but also increase the residence time of the microcapsules for 72h in the colon.

Preparation and characterization of acetylated starch nanoparticles as drug carrier: Ciprofloxacin as a model

The objective of this study was to characterize in-vitro the potential of acetylated corn starch (ACS) particles as a matrix for the delivery of ciprofloxacin (CFx). ACS was successfully synthesized and optimized by the reaction of native corn starch using acetic anhydride and acetic acid with low and high degrees of substitution (DS). The nanoprecipitation method was applied for the formation of the ACS-based nanoparticles, by the dropwise addition of water to acetone solution of ACS under stirring. The effects of acetylation and nanoprecipitation on the morphology and granular structure of ACS samples were examined by the FT-IR, XRD, DSL and SEM techniques. The efficiency of CFx loading was also evaluated via encapsulation efficiency (EE) in ACS nanoparticles. The average degree of acetyl substitution per glucose residue of corn starch was 0.33, 2.00, and 2.66. The nanoparticles size of the ACS and ACS-loaded with CFx were measured and analyzed relative to the solvent:non-solvent ratio. Based on the results, ACS nanoparticles with DS of 2.00 and water:acetone of 3:1 had 312nm diameter. Increasing DS in starch acetate led to increase in the EE from 67.7 to 89.1% and with increasing ratio of water/acetone from 1:1 to 3:1, the EE raised from 48.5 to 89.1%. X-ray diffraction indicated that A-type pattern of native starch was completely transformed into the V-type pattern of acetylated starch. The scanning electron microscopy showed that the different sizes of pores formed on the acetylated starch granules were utterly converted into the uniform-sized spherical nanoparticles after the nanoprecipitation.

Synthesis, characterization and in vitro drug release of cisplatin loaded Cassava starch acetate–PEG/gelatin nanocomposites

The aim of the present study is to examine the feasibility of Cassava starch acetate (CSA)–polyethylene glycol (PEG)–gelatin (G) nanocomposites as controlled drug delivery systems. It is one of the novel drug vehicles which can be used for the controlled release of an anticancer drug. Simple nano precipitation method was used to prepare the carriers CSA–PEG–G nanocomposites and they were used for entrapping cisplatin (CDDP). Through FT-IR spectroscopy, the linking among various components of the system was proved and with the help of scanning electron microscope and transmission electron microscopy (TEM), the surface morphology was investigated. The particle sizes of the CSA–CDDP, CSA–CDDP–PEG and CSA–CDDP–PEG–G polymer composites were between 140 and 350nm, as determined by a Zetasizer. Drug encapsulation efficiency, drug loading capacity and in vitro release of CDDP were evaluated respectively. The findings revealed that the cross linked CSA–PEG–G nanocomposites can be a potential polymeric carrier for controlled delivery of CDDP.

Endophytic Bacteria Isolated from Nipa Palm (Nypa fruticans) in Bulacan, Philippines

The nipa (Nypa fruticans) environment has limited nutrients along with soil salinity, but sustainably high productivity is observed for this palm. Its productivity is supported by indefinite mechanisms for its fertility maintenance, in which symbiotic microbes are involved. In this study, screening of endophytic bacteria examined their multiple plant growth-promoting traits. These include the production of indole acetic acid (IAA), phosphate solubilization, nitrogen fixation, and starch hydrolysis as potential microbial inoculants to upland rice. Twelve endophytic bacterial strains were isolated from nipa palm in Bulacan, Philippines. All bacterial isolates produced IAA in culture. Ten of the 12 isolates dissolved precipitated tricalcium phosphate as shown by clearing zones around isolates grown in Pikovskaya’s medium. Five isolates were nitrogen-fixing bacteria while four hydrolyzed starch. Promising bacteria will be selected from the 12 isolates for further study. Other researchers have proven the ability of Burkholderia, bacteria isolated from nipa palm to endophytically colonize rice, promoting both plant growth and rice grain yield. Hence, it is possible that the isolated endophytic bacteria from nipa palm may also act as plant growth enhancers to other crops including rice. Keywords - Microbiology, endophytic bacteria, growth-promoting activities, nipa palm, Bulacan, Philippines

Preparation and Characterization of Cassava Leaves/ Cassava Starch Acetate Biocomposite Sheets

Biocomposite packaging sheets made of cassava leaves (CL) and cassava starch acetate (CSA) were successfully prepared in this study, and using the surface impregnation method, the sheets were able to obtain desirable properties. The CL sheets were impregnated with CSA at various concentrations to improve the sheets’ performance. This newly developed packaging material exhibited low moisture uptake and had a viable tear index value when the CSA impregnation level was 6%. Moreover, the sheets’ properties were comparable to that of available paper or plastic sheets, having low moisture uptake, good wetting time and tear strength, smooth sheet formation, and enhanced thermal stability. Using agro-based materials from cassava plants for packaging materials could reduce the dependency on paper- and plastic-based packaging. Suitable utilization of this material includes as bag, carton and wrap.

Estimation of Young’s modulus of pharmaceutical tablet obtained by terahertz time-delay measurement

In this paper, it is suggested that Young’s modulus of pharmaceutical tablets with different porosity can be estimated from terahertz (THz) pulse time delay. We demonstrate such a possibility using a training set of tablets compressed from starch acetate. Once the mechanical properties are taught to the THz measurement system, using an ideal tablet as a reference, it is possible to get information about the Young’s modulus of the tablet. Here, we show that there are optical counterparts of classical mechanical laws that couple the Young’s modulus and porosity of the tablet.

Preparation and characterization of glycoprotein-resistant starch complex as a coating material for oral bioadhesive microparticles for colon-targeted polypeptide delivery.

For effective oral delivery of polypeptide or protein and enhancement their oral bioavailability, a new resistant starch-glycoprotein complex bioadhesive carrier and an oral colon-targeted bioadhesive delivery microparticle system were developed. A glycoprotein, concanavalin A (Con A), was successfully conjugated to the molecules of resistant starch acetate (RSA), leading to the formation of resistant starch-glycoprotein complex. This Con A-conjugated RSA film as a coating material showed an excellent controlled-release property. In streptozotocin (STZ)-induced type II diabetic rats, the insulin-loaded microparticles coated with this Con A-conjugated RSA film exhibited good hypoglycemic response for keeping the plasma glucose level within the normal range for totally 44-52 h after oral administration with different insulin dosages. Oral glucose tolerance tests indicated that successive oral administration of these colon-targeted bioadhesive microparticles with insulin at a level of 50 IU/kg could achieve a hypoglycemic effect similar to that by injection of insulin at 35 IU/kg. Therefore, the potential of this new Con A-conjugated RSA film-coated microparticle system has been demonstrated to be capable of improving the oral bioavailability of bioactive proteins and peptides.

Toughening polylactide with polyether-block-amide and thermoplastic starch acetate: Influence of starch esterification degree

Native corn starch was esterified with acetic anhydride and plasticized with glycerol to give the thermoplastic starch acetate (TPSA). TPSA was blended with polylactide (PLA) and polyether-block-amide-graft-glycidyl methacrylate (PEBA-g-GMA) to obtain biodegradable PLA/PEBA-g-GMA/TPSA blends with high notched impact resistance and low cost. Compared with PLA/PEBA-g-GMA blends, as much as 9wt% expensive PEBA-g-GMA elastomer could be substituted by the slightly acetylated thermoplastic starch while retaining high impact strength. The mechanical properties depended on the esterification degree of starch acetate. The impact strength, tensile strength and elongation at break increased to the peak value with increasing the esterification degree from 0 to 0.04, thereafter they decreased on further increasing the esterification degree. The morphological results showed that the TPSA particles were smaller and more uniform at the optimum esterification degree of 0.04, leading to the peak value of the mechanical properties.

Preparation and Characterization of Bio-based Degradable Plastic Films Composed of Cellulose Acetate and Starch Acetate

Bio-based degradable plastic is superior to petroleum-based plastic in terms of environmental protection and preservation of resources. A novel cross-linking system using tributyl citrate (TBC) as a cross-linking agent was used to create a bio-based degradable plastic via acetylation modified starch acetate (SA) and cellulose acetate (CA). Fourier transform infrared spectroscopy of the new plastic films revealed that a cross-Claisen ester condensation reaction had indeed occurred among TBC, CA and SA in the cross-linking system. Thermogravimetric analysis, X-ray diffraction, Scanning electron microscopy and mechanical properties tests confirmed that the fabricated films had mechanical properties and thermal stability that were comparable to conventional plastic films. A degradation-in-soil test showed that the fabricated films have controllable biodegradation properties by adjusting the amount of SA added. The tensile stress of two films—one with mass ratio of SA to CA1:3 and the other with mass ratio of 2:3—reached 3.5 and 3.0 MPa, respectively, the corresponding tensile strains were 22.3 and 17.9 %. The highest thermal stability temperature for both films was 205 °C. After being buried in soil for 35 days, the first film was 36 % degraded, and the second film was 41 % degraded. This paper is expected to promote the study and fabricate of bio-based degradable plastic film.

Acetylation of rice starch in an aqueous medium for use in food

The degree of acetylation controls the use of starch acetate, since the FDA (Food and Drug Administration USA) recommends an acetyl groups' percentage below 2.5 g/100g for a food application. The objective of this work was to evaluate the effects of the acetic anhydride concentration, in an aqueous solution, on the degree of acetylation, in physical, thermal, pasting and morphological properties, and enzymatic susceptibility on rice starch acetylated with the acetyl groups' percentage up to 2.5 g/100g. The rice starch was acetylated using different concentrations of acetic anhydride (5 g/100g, 10 g/100g and 20 g/100g, starch db). Acetylation increased the peak viscosity, breakdown, final viscosity, retrogradation and pasting temperature and reduced the hardness of the gels, as well as their adhesiveness and gumminess; however this did not affect the morphology and susceptibility to hydrolysis by the α-amylase of the starch. The acetylated starches using 10 and 20 g/100g acetic anhydride showed lower swelling power and solubility compared to native starch.

Ninety-Day Oral Toxicity Assessment of an Alternative Biopolymer for Controlled Release Drug Delivery Systems Obtained from Cassava Starch Acetate.

The large consumption of biodegradable films from cassava starch acetate (FCSA) as ingredients in food and pharmaceutical products requires the assessment of the possible toxicity of these products. The aim of this study was to investigate the toxicity of biodegradable film from cassava starch acetate after oral exposure of Wistar rats for 90 days. The amount of food consumed and the body weight were weekly monitored. Blood and urine samples were obtained for the assessment of serum parameters and renal function. Histopathological analyses in target organs were also performed. No evidence of clinical toxicity in hematological, biochemical, or renal parameters in the FCSA-treated animals was found. In addition, relative organ weight and histopathological evaluations did not differ between groups treated with FCSA and control. Data obtained suggest that the subchronic exposure to FCSA does not cause obvious signs of toxicity in Wistar rats, indicating possible safety of this biofilm.

Physicochemical and drug release characteristics of acetylated starches of five Lagenaria siceraria cultivars

Modified starches play a crucial role in the pharmaceutical industries in controlling the drug release at a pre-determined rate. The effect of acetylation on the physicochemical and drug release characteristics of the starches from five different Indian L. siceraria cultivars was investigated. Starches isolated from the seeds of L. siceraria were subjected to varying degrees of acetylation. Using a range of characterization methods including amylose content, elemental analysis, light transmittance, swelling power, scanning electron microscopy, FT-IR and X-ray diffraction, the effect of acetylation was determined. The swelling power of starch acetates improved significantly (P<0.05) with the increase in degree of substitution. The increase in swelling shows that acetylation improved the accessibility of an amorphous area to the water. The formation of V-type of complex crystalline structures confirmed the acetylation of L. siceraria starch. Modification in the crystalline structure of starch acetate retarded the drug release, which is controlled by water uptake. The starch acetates from all the cultivars showed better sustained release properties with the increase in degree of substitution. Drug release through the swellable matrix was found to be controlled by fickian diffusion from the gel layer as indicated by Korsmeyer–Peppas models (R2) 0.9885–0.9984.

Research on the water‐holding capacity of pork sausage with acetate cassava starch

The water‐holding capacity properties of native and acetate cassava starch were evaluated by freeze–thaw stability and XRD. The results indicated that acetate starch was suitable to be used in sausage for its more stable and lower retrogradation properties compared to native starch. The water‐holding capacity (WHC) of pork sausages with acetate starch was analyzed by NMR T2 relaxometry, magnetic resonance imaging (MRI), differential scanning calorimeter (DSC) and SEM. NMR T2 relaxometry and MRI displayed the significant effect of acetate starch on the water content in sausages. Water‐holding capacity of sausages first increased then decreased with increase of acetate starch. The sausage with 5% w/w acetate starch had the highest content of immobilized water. The result was consistent with the data indirectly obtained from DSC. SEM analysis demonstrated that the sausage with 5% w/w acetate starch had appropriate structure and pore size to hold water. Therefore, we concluded that the sausage with 5% w/w acetate starch had the best WHC property in pork sausages.

Strength of cellulosic fiber/starch acetate composites with variable fiber and plasticizer content

In this experimental study, the performance of injection-molded short flax and hemp fibers in plasticized starch acetate were analyzed in terms of strength. Parameters involved in the analysis are a variable fiber and plasticizer content. The measured strength of the composites varies in the range of 12–51 MPa for flax fibers and 11–42 MPa for hemp fibers, which is significantly higher than the properties of the unreinforced starch acetate matrix. The micro-structural parameters used in modeling of composite strength were obtained from optical observations and indirect measurements. Some of these parameters were qualitatively verified by X-ray microtomography.

Structural changes and triacetin migration of starch acetate film contacting with distilled water as food simulant

This work studied the structural changes and the migration of triacetin plasticizer in starch acetate films in the presence of distilled water as food simulant. Fourier-transform infrared spectroscopy result showed that the macromolecular interaction was enhanced to form compact aggregation of amorphous chains. The characterization of aggregation structures via wide and small angle X-ray scattering techniques indicated that the orderly microregion was compressed and the crystallites inside were “squeezed” to form interference and further aggregation. The compact aggregation structures restricted the mobility of macromolecules, triacetin and water molecules. The overall kinetic and the diffusion model analysis manifested that Fick's second law was the predominant mechanism for the short-term migration of triacetin. The increasing relaxation within film matrix caused the subsequent migration to deviate from Fick's law. The safe and reasonable application of the starch-based materials with restrained plasticizer migration could be accomplished by controlling the molecular interaction and aggregation structures.

Individual and combined effects of modified starch, bentonite and their composite powder with HPMC on the performance of cement mortars

Abstract A series of acetate starch was synthesized and mixed with bentonite to prepare acetate starch/bentonite composite as a novel additive in order to improve the thixotropic property of cement mortar. The thixotropic index and water retention value of the fresh cement mortar containing acetate starch, bentonite, and acetate starch/bentonite composite, respectively, were measured with and without hydroxypropyl methyl cellulose ether (HPMC). Acetate starch with the degree of substitution (DS) of about 0.5 provided the largest increase in the thixotropic index of the cement mortar. Application of HPMC gave high water retention ability and viscosity to the mortar, but the thixotropic property was not improved. Adding acetate starch or starch/bentonite composite to the mortar can increase its thixotropic index, whereas no significant improvements on the water retention ability and viscosity of mortars were observed. By the combined use of acetate starch/bentonite composite with HPMC, the water retention value (WRV) of the mortar was as high as 98%, and its thixotropic index increased from 4.06 to 5.30, with a high value of viscosity.

Synthesis of Starch Acetates and Electrospinning

Acetylation of high amylose (50%) maize starch to high degree of substitution (DS) was synthesised by reacting starch with acetic anhydride using sodium hydroxide as the catalyst. Starch Acetate was dissolved in Dimethyl Sulphoxide (DMSO), the DS of which ranged from 0.8 to 1.8. Ultrafine fibers were made by the method of electrospinning. FTIR, NMR and SEM were used to characterize the structure and surface morphology of the product.

Design and evaluation of glipizide CR tablets employing starch acetate as rate controlling matrix former

Background/ObjectivesIn the present work, starch acetate was synthesized, characterized and evaluated as effective release retarding matrix materials. MethodsMatrix tablets of glipizide were formulated employing starch acetate in different proportions of drug and polymer and the tablets were evaluated for drug release kinetics and mechanism. ResultsStarch acetate (SA) was prepared by acetylation of potato starch with acetic anhydride in alkaline medium. The percent acetylation was 42.38% and the degree of substitution was 2.75. Glipizide (10 mg) matrix tablets prepared using starch acetate as matrix former in different concentrations gave slow and controlled release more than 24 h. Glipizide release from the tablets formulated was slow and depends on the concentration (%) of starch acetate in the matrix tablets and nature/type of diluent. A linear relationship was found out between percent of polymer, starch acetate and release rate (K0) of the tablets. The controlled release characteristics of the starch acetate matrix tablets of the drug remained unaltered during short time accelerated stability study. ConclusionsStarch acetate was found suitable as matrix former for controlled release and the matrix tablets of glipizide formulated employing starch acetate gave controlled release of glipizide over 24 h.

Production of Starch Acetate Films with Addition of Bacterial Cellulose Nanofibers

Production of Starch Acetate Films with Addition of Bacterial Cellulose Nanofibers

PEGylated starch acetate nanoparticles and its potential use for oral insulin delivery

A novel controlled release formulation has been developed with PEGylated starch acetate nanoparticles. Biodegradable polymers, such as starch, have been studied for various pharmaceutical applications because of their biocompatibility and biodegradability. Starch acetate is one of the hydrophobic biodegradable polymers currently being used or studied for controlled drug delivery. Polyethylene glycol was conjugated with starch acetate, to obtain an amphiphilic polymeric derivative. On its incubation with insulin solution at the critical micelle concentration, self-aggregated nanoparticles with mean particle size of 32nm are formed. These self-aggregated nanoparticles with associated insulin have enhanced encapsulation efficiency. The mean particle size of these nanoparticles increased with the increase in the molecular weight of PEG. Present study indicated that PEGylated starch acetate nanoparticles are highly bioadhesive and can be utilized as a carrier system for controlled delivery of insulin or other proteins for various therapeutic applications.