Pullulan Films Research Articles

In vitro and in vivo evaluation of gentamicin sulphate-loaded PLGA nanoparticle-based film for the treatment of surgical site infection

The study focuses on the in vitro and in vivo evaluation of the developed gentamicin sulphate (GS)-loaded poly lactic-co-glycolic acid (PLGA) nanoparticle (PNP)-based pullulan film (PNP-F). Sterilization being an essential pre-requisite for the dosage form was carried out using ethylene oxide. Post-sterilization, PNP-F was evaluated for mechanical properties, percentage drug loading, antimicrobial effectiveness study, test for sterility and in vitro dissolution study using Strat-M® membrane. In vitro dissolution study revealed that GS gradually released from PNP-F and the highest cumulative percentage drug release was found to be 86.76 ± 0.03% at 192h. Wound healing assay was performed to study the effect of PNP-F over migratory potential of dermal fibroblast cells (NIH-3T3) in the presence of micro-organisms, Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA). PNP-F inhibited the growth of PA and SA, allowing the growth of fibroblast cells indicating its suitability for application. In vivo study of surgical site was performed by superficial incision model in Wistar rats. Measurement of in vivo incision healing confirmed faster wound healing in the incision which received PNP-F compared to marketed cream containing GS. Graphical abstract.

Release kinetics of cinnamaldehyde, eugenol, and thymol from sustainable and biodegradable active packaging films

Active packaging films can be formulated with biodegradable polymer loaded with natural antimicrobial compounds (NAC) as biodegradable alternatives to traditional plastic packaging for food. Essential oil compounds, naturally found in the plants, have antimicrobial activity against microorganisms. In this work, they are encapsulated in liquid lipid nanoparticles (LLN) or solid lipid nanoparticles (SLN) to control and enhance their solubility and stability and control kinetic release. In this study, the release kinetics of thymol, cinnamaldehyde, and eugenol, from pullulan-based films were studied as a function of lipid structure (liquid vs solid) and carrier particle concertation. The crystallization temperature of SLN (10.2 °C) decreased with incorporation of NAC (6.8 °C in SLN loaded with 1 % cinnamaldehyde). Increasing NAC significantly decreased (p < 0.05) the crystallization temperature of SLN. The SLN structure was similar in films to emulsions as their melting and crystallization temperatures were similar (p > 0.05). The NAC release rate from SLN films was twice than that from LLN films due to higher aqueous partitioning. The release rate in SLN films increased 100 %, 50 %, and 5 % for thymol, eugenol, cinnamaldehyde, respectively, when NAC concertation in the particles increased from 1 % to 2 %. Thymol had highest release rate (0.93 ppm/min) from SLN loaded with 2 % NAC films than that of eugenol and cinnamaldehyde (0.40 and 0.15 ppm/min, respectively). This study shows that the NAC-loaded pullulan films can be used as active antimicrobial packaging film for food applications with controlled release of active compounds.

Preparation and characterization of pullulan derivative antibacterial composite films.

The preparation of an antibacterial film is imperative for the preservation and transportation of food. In the present work, we prepared a pullulan derivative/sodium alginate composite film. This composite film exhibited an excellent film-forming ability and water vapor barrier. In addition, with 11% light transmittance in the visible region, this film exhibited worthwhile light barrier properties. Further, the addition of sodium alginate improved the mechanical properties of the composite film (34MPa). The active amino groups on the pullulan derivative backbone induced antimicrobial activity against both E. coli and S. aureus. This study can provide an essential guideline for the preparation of antibacterial food packaging films in the future.

Preparation and characterization of chitosan - pullulan blended edible films enrich with pomegranate peel extract

Preparation and characterization of chitosan - pullulan blended edible films enrich with pomegranate peel extract

The role of chitosan as coating material for nanostructured lipid carriers for skin delivery of fucoxanthin.

Fucoxanthin (FUCO) is a marine carotenoid characterized by antiproliferative properties against hyperproliferative cells. The aim of this work was to design and develop nanostructured lipidic carriers (NLCs) based on bacuri butter and tucumã oil and loaded with FUCO, intended for skin application to prevent skin hyperproliferative diseases and in particular psoriasis. The presence of FUCO should control the hyperproliferation of skin diseased cells and the lipids forming the NLC core, rich in antioxidants and characterized by wound healing properties, should favor the restoring of skin integrity. NLCs were coated with chitosan (CS) to improve their biopharmaceutical properties (bio/mucoadhesion and wound healing) and to combine the advantages of lipidic nanoparticles with the biological properties of CS. Chitosan coated and non-coated NLC were prepared by means of high shear homogenization and characterized for chemico-physical and biopharmaceutical properties (in vitro biocompatibility and cell uptake towards normal dermal human fibroblasts). Moreover, the pharmacological activity of FUCO loaded in NLCs was assessed in psoriatic-like cellular model. NLCs were characterized by dimensions ranging from about 250 to 400 nm. Moreover, the CS coating and FUCO loading determined an increase of size. Moreover, TEM and zeta potential analysis confirmed the presence of CS coating on nanoparticle surface, thus conferring to nanoparticle good bioadhesion properties. NLCs uptake in fibroblasts was observed and NLC-FUCO-CS caused a reduction of cell viability with a less marked effect in fibroblasts rather than in psoriatic cells, highlighting the capability of this system to control skin hyperproliferation and inflammation. The loading of NLC-FUCO-CS in pullulan film should render NLCs application easy, without impair prompt interaction of the drug with the skin. Considering the overall results skin application of CS coated NLCs loaded with FUCO seems a promising approach to control skin hyperproliferation and to preserve skin integrity in psoriatic skin.

Effect of nano-TiO2 on the physical, mechanical and optical properties of pullulan film

In this study, effects of nano-TiO2 on the microstructural, physical, mechanical and optical properties of pullulan films were investigated. The results showed that the addition of nano-TiO2 improved the water vapor barrier properties of the film due to the tortuous path formed by nano-TiO2. When the concentration of nano-TiO2 was 0.04 g/100 mL, the tensile strength of the film showed a maximum value (15.99 MPa). The elongation at break of the film continued to decrease with the increase of nano-TiO2. The TEM analysis showed that higher concentration of nano-TiO2 would cause greater aggregation. Meanwhile, the results of FTIR and low-field NMR indicated that the miscibility between pullulan and nano-TiO2 was due to the formation of intermolecular hydrogen bonds during film formation. Furthermore, the addition of nano-TiO2 significantly improved the film barrier properties to ultraviolet light.

Effect of lactoferrin on physicochemical properties and microstructure of pullulan-based edible films.

Pullulan is a polysaccharide polymer commonly used to produce edible films. However, pure pullulan film is usually brittle and very hydrophilic, which limit its use in both food and pharmaceutical fields. The objective of this research is to improve the structural and mechanical properties of pullulan film by incorporating globular protein lactoferrin (LF). The incorporation of LF increased the surface hydrophobicity and decreased the water vapor permeability (WVP) of pullulan film. The presence of low concentrations of LF (< 0.03%) has no significant influence on tensile strength (TS) and elongation at break (EAB) of pullulan film. However, further increase of LF concentration to levels > 0.03% resulted in a film-weakening effect. LF molecules aggregated with each other during the film-producing process, which presented as spherical particles from the observation of microscopy. LF aggregates dispersed homogeneously throughout the pullulan matrix and their size increased with increasing concentration. Analysis from Fourier transform infrared spectroscopy indicated that the secondary structure of LF molecules was modified during the drying process. It is possible to increase the hydrophobicity of pullulan film while maintaining its mechanical properties. The produced composite film can be potentially used for food and medical packaging. © 2019 Society of Chemical Industry.

Ready-to-use thermally stable mastermix pills for molecular biology applications.

Rolling circle amplification (RCA), polymerase chain reaction (PCR), and loop-mediated isothermal amplification (LAMP), are powerful tools that can be used for gene manipulation, pathogen detection, and infectious disease diagnostics. However, these techniques require trained personnel, as the pipetting steps involved can lead to contamination and, consequently, erroneous results. Furthermore, many of the reagents used in molecular biology are thermally labile and must be kept within a cold-chain. In this article, we present a simple and cost-effective method that allows molecular biology reagents to be thermally stabilized into ready-to-use mastermixes via drying in pullulan and trehalose films. Our experimental results demonstrate that this method is capable of preserving the activity of RCA, PCR, LAMP, ligase, polynucleotide kinase, and Klenow fragment mastermixes for at least 3 months at ambient conditions. Thus, stabilizing reagents via drying in pullulan and trehalose film may allow for a drastic reduction in the number of pipetting steps and the elimination of the need for a cold chain. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2764, 2019.

Optical and mechanical properties of pullulan films studied by uniaxial stretching

Optical properties of pullulan films were examined before and after uniaxial stretching to obtain the specific molecular characteristics of pullulan. It was shown that the specific optical rotation for pullulan film was not affected by uniaxial stretching, being the same as that for pullulan in aqueous solution. Combined with the mechanical measurement, the stress-optical coefficient for pullulan was estimated as a material constant on the basis of the modified stress-optical rule. The birefringence was positive and increased with time during the stress relaxation of uniaxially-stretched pullulan film. A set of the stress-optical coefficients CR=1.9×10−9Pa−1 and CG=−4.6×10−12Pa−1 were obtained, where the subscripts R and G stand for the rubber and the glass components respectively.

Toward Improving Medication Adherence: The Suppression of Bitter Taste in Edible Taste Films.

Bitter taste is aversive to humans, and many oral medications exhibit a bitter taste. Bitter taste can be suppressed by the use of inhibitors or by masking agents such as sucralose. Another approach is to encapsulate bitter tasting compounds in order to delay their release. This delayed release can permit the prior release of bitter masking agents. Suppression of bitter taste was accomplished by encapsulating a bitter taste stimulus in erodible stearic acid microspheres, and embedding these 5 µmeter diameter microspheres in pullulan films that contain sucralose and peppermint oil as masking agents, along with an encapsulated masking agent (sucralose). Psychophysical tests demonstrated that films which encapsulated both quinine and sucralose produced a significant and continuous sweet percept when compared to films without sucralose microspheres. Films with both quinine and sucralose microspheres also produced positive hedonic scores that did not differ from control films that contained only sucralose microspheres or only empty (blank) microspheres. The encapsulation of bitter taste stimuli in lipid microspheres, and embedding these microspheres in rapidly dissolving edible taste films that contain masking agents in both the film base and in microspheres, is a promising approach for diminishing the bitter taste of drugs and related compounds.

Affect the Cross Linking Degree and Polymer Composition on the Mechanical Properties of Poly (vinyl alcohol)/ Pullu-lan Films

In this study Cross-linked PVA/Pullulan film was prepared. Cross-linking reaction done by addi-tion of gluteraldehyde at different reaction time (10,30and 60) min. Chemical interaction, me-chanical, thermal properties, water solubility and film morphology was studied for cross-linked PVA/Pullulan, PVA and Pullulan only. Thus FTIR investigated formation of hydrogen bonding between pullulan and PVA with (GA). Tensile strength, tensile modulus and elongation (%) at break for PVA/Pullulan film was improved with addition of (GA) as the reaction time proceed equivalent with increasing PVA content

Drying process of pullulan edible films forming solutions studied by low-field NMR

The dynamics of water in pullulan film-forming solutions during drying were investigated by low-field nuclear magnetic resonance. At the begin of drying, two transverse relaxation times (T2) at around 32.77 and 2149ms were attributed to bound and free waters in pullulan samples, respectively. An additional T2 value, ascribed to the tightly bound water in entanglement zones of pullulan chains, appeared at around 3.51ms as the drying process continued (beyond 1080min of drying time). The observed three relaxation times revealed the multi-exponential relaxation behavior of water in pullulan. Moreover, the polymer exhibited spatial heterogeneity with increasing drying time from 1200 to 1920min. On the basis of diffusive and chemical exchange model, the dimension range of pullulan network decreased from 7.69-32.66 to 4.73-18.14µm as the pullulan films solidified. Furthermore, the rate of chemical exchange between water and pullulan significantly increased at the later stage of drying process.

Characterization of orally disintegrating films: A feasibility study using an electronic taste sensor and a flow-through cell

In the early development stage of orally disintegrating films (ODFs), suitable evaluation methods must be used. The aim of this study was to demonstrate the feasibility of using an electronic taste sensor and a flow-through cell for ODFs. A pullulan film loaded with donepezil hydrochloride (DH) was designed, as a model ODF. The film was prepared using the solution/solvent casting method. First, the dissolution profiles were compared by using a paddle method (PD) and a flow-through cell method (FT) under three flow rates. Dissolution tests using both methods were carried out successfully. Secondly, the bitterness of ODFs was determined by a new system combining a flow-through cell apparatus and an electronic taste sensor apparatus. The results indicated that the FT method can collect eluate for the bitterness test. They also suggested that these methods are useful for evaluating ODFs. The sensor output was strongly correlated with the dissolution behavior at the initial stage of administration. This new system with a flow-through cell and an electronic taste sensor could be used to evaluate the palatability of ODFs and to improve film formulation.

RNA Protection is Effectively Achieved by Pullulan Film Formation.

RNA is a functionally versatile polymer but suffers from susceptibility to spontaneous and RNase-catalyzed degradation. This vulnerability makes it difficult to preserve RNA for extended periods of time, thus limiting its use in various contexts, including practical applications as functional nucleic acids. Here we present a simple method to preserve RNA by pullulan (a complex sugar produced by Aureobasidium pullulans fungus) film formation. This strategy can markedly suppress both spontaneous and RNase degradation. Importantly, the pullulan film readily dissolves in aqueous solution, thus allowing retrieval of fully functional RNA species. In order to illustrate the advantage of this protective method in a practical application, we engineered a simple paper sensor containing a bacteria-detecting RNA-cleaving DNAzyme. This detection capability of the device was unchanged after storage at room temperature for six months.

Orientational order in surface layers of pullulan films

A study was made of spontaneous surface birefringence observed in pullulan films when a tilted polarized beam is passed through a plain polymer film. Birefringence was explored as a function of the angle of beam incidence and the film thickness. The orientational order parameter was estimated for pullulan chains located in the near-surface layers of films. The results were compared with data from earlier studies of other polysaccharides.

Improvement on Physical Properties of Pullulan Films by Novel Cross-Linking Strategy.

Pullulan based films possess several advantages, including high transparency, low toxicity, good biodegradability, good mechanical properties, and low oxygen permeability, are preferable for food packaging. The application of pullulan films on food packaging, however, has inherent disadvantage of high water solubility. In this study, glutaraldehyde and glycerol were used as the cross-linking reagent and the plasticizer respectively to improve water resistance and physical properties of the pullulan films. Effects of cross-linking degree on physical properties, including water absorptions, swelling behaviors, water vapor permeability and tensile strengths of films were evaluated. FTIR results demonstrated that the pullulan films were successfully cross-linked by glutaraldehyde. The tensile strength of pullulan films could be enhanced significantly (P < 0.05) when glutaraldehyde was between 1% and 5% (w/w); nevertheless, the amount of glutaraldehyde above 20% (w/w) led to films brittleness. With the addition of glycerol as a plasticizer enhanced the extensibility of films as well as the hydrophilicity, resulting in higher water vapor permeability.

Effect of plasticizers on the physico-mechanical properties of pullulan based pharmaceutical oral films

The effect of different plasticizers (glycerol, vitamin E TPGS and triacetin) and their concentrations on the physico-mechanical properties of pullulan based oral films was studied. A full factorial (32) design of experiments was used. Elastic modulus, tensile strength, elongation at break and disintegration time were selected as response variables. Modulated differential scanning calorimeter (MDSC) was used for determining glass transition temperature (Tg) of pullulan films. The surface morphology of films was evaluated by SEM, while ATR-FTIR was used to obtain a molecular level understanding of polymer-plasticizer interactions. The DoE analysis allowed for the modelling of tensile strength and elongation at break. The highest elongations were observed in glycerol at 20% w/w. Majority of the films disintegrated within one minute without significant differences. ATR-FTIR spectra of pullulan alone and different plasticizer blend films show characteristic molecular interactions. The present study concluded that glycerol is suitable plasticizer compared to others for manufacturing pullulan based oral films.

Preparation and Characterization of Pullulan-Soy Protein Concentrate Blended Film Incorporated With Zataria multiflora and Artemisia biennis Essential Oils

Background: Adding antimicrobial agents to biodegradable packaging can make a coating that can protect foods and drugs against microbial contamination. Objectives: To evaluate the physical and mechanical properties and antimicrobial activity of soy protein concentrate (SPC) and pullulan films incorporated with Zataria multiflora (ZM) and Artemisia biennis (AB) essential oils (Eos). Methods: In this study, the pullulan and SPC solutions were mixed in a 50:50 ratio and EOs from ZM or AB were incorporated into the film solution at various concentrations. The casting/solvent evaporation method was used for film formation. Physical and mechanical characterization was determined, and the antimicrobial activities of the films were evaluated against Staphylococcus aureus, Lactobacillus plantarum, and Escherichia coli by agar diffusion method. The minimum inhibitory concentration (MIC) was also identified. Results: The prepared films were flexible without pores and homogeneous. The addition of EOs significantly increased the thickness and elongation at break but reduced the tensile strength, water vapor permeability, and solubility in water of the films (P < 0.05). Unlike in the control film, the addition of EOs resulted in a dark and yellow film appearance as evidenced by the lower L and greater ΔE and b. In all concentrations, the intensity of the antimicrobial activity of AB was significantly lower than that of ZM (P < 0.05). E. coli and S. aureus had the highest and the lowest resistance to the antimicrobial effect of Eos, respectively. Conclusions: These findings may lead to the utilization of this new antibacterial film that has the potential to be used as packaging material.

Preservation of Brussels Sprouts by Pullulan Coating Containing Oregano Essential Oil

In this study, the effectiveness of pullulan (a fungal polysaccharide) film containing oregano essential oil (OEO) at 1.0 to 10.0% was evaluated against bacteria, yeasts, and molds. The quality of the sprouts, as determined by weight loss, color, and appearance, was monitored during storage at 2 and 16°C. An organoleptic evaluation of odor preference and odor acceptability of OEO on the Brussels sprouts was also conducted. The antimicrobial activity of pullulan films with OEO increased significantly with the increase in OEO concentration (1 to 10%). Pullulan films with OEO were more effective for inhibiting the growth of yeasts and molds than for inhibiting gram-positive and gram-negative bacteria. Pullulan with 1.0% OEO was an effective combination and was used subsequently as the base coating for maintaining the safety and quality of fresh Brussels sprouts stored at 16°C for 14 days. The pullulan coating containing 1.0% OEO reduced Aspergillus niger populations by 2 log CFU/g. This coating also reduced weight loss in the sprouts. Compared with uncoated Brussels sprouts, the percent weight loss after 14 days was reduced in samples coated with pullulan and with pullulan plus 1% OEO by 3.81 and 6.06%, respectively, after storage at 2°C and by 8.04 and 9.30%, respectively, after storage 16°C. The coating also significantly reduced changes in general appearance and color during storage. Evaluation of the organoleptic properties indicated that pullulan containing OEO had only a slight detrimental effect on odor properties. Incorporating OEO into a delivery system for antimicrobial compounds in pullulan coatings extended the microbiological shelf life of Brussels sprouts.

Preparation and characterization of fast dissolving pullulan films containing BCS class II drug nanoparticles for bioavailability enhancement

The aim of this study is to assess pullulan as a novel steric stabilizer during the wet-stirred media milling (WSMM) of griseofulvin, a model poorly water-soluble drug, and as a film-former in the preparation of strip films via casting–drying the wet-milled drug suspensions for dissolution and bioavailability enhancement. To this end, pullulan films, with xanthan gum (XG) as thickening agent and glycerin as plasticizer, were loaded with griseofulvin nanoparticles prepared by WSMM using pullulan in combination with sodium dodecyl sulfate (SDS) as an ionic stabilizer. The effects of drug loading and milling time on the particle size and suspension stability were investigated, as well as XG concentration and casting thickness on film properties and dissolution rate. The nanosuspensions prepared with pullulan–SDS combination were relatively stable over 7 days; hence, this combination was used for the film preparation. All pullulan-based strip films exhibited excellent content uniformity (most <3% RSD) despite containing only 0.3–1.3 mg drug, which was ensured by the use of precursor suspensions with >5000 cP viscosity. USP IV dissolution tests revealed fast/immediate drug release (t80 < 30 min) from films <120 μm thick. Thinner films, films with lower XG loading, or smaller drug particles led to faster drug dissolution, while drug loading had no discernible effect. Overall, these results suggest that pullulan may serve as an acceptable stabilizer for media milling in combination with surfactant as well as a fast-dissolving film former for the fast release of poorly water-soluble drug nanoparticles.