Plasticized Starch/Agar Composite Films: Processing, Morphology, Structure, Mechanical Properties and Surface Hydrophilicity

Natural biopolymers, which are renewable, widely available, biodegradable, and biocompatible, have attracted huge interest in the development of biocomposite materials. Herein, formulation–property relationships for starch/agar composite films were investigated. First, rapid visco analysis was used to confirm the conditions needed for their gelation and to prepare filmogenic solutions. All the original crystalline and/or lamellar structures of starch and agar were destroyed, and films with cohesive and compact structures were formed, as shown by SEM, XRD, and SAXS. All the plasticized films were predominantly amorphous, and the polymorphs of the composite films were closer to that of the agar-only film. FTIR results suggest that the incorporation of agar restricted starch chain interaction and rearrangement. The addition of agar to starch increased both tensile strength and elongation at break, but the improvements were insignificant after the agar content was over 50 wt.%. Contact angle results indicate that compared with the other samples, the 4:6 (wt./wt.) starch/agar film was less hydrophilic. Thus, this work shows that agar dominates the structure and properties of starch/agar composites, and the best properties can be obtained with a certain starch/agar ratio. Such composite polysaccharide films with tailored mechanical properties and surface hydrophilicity could be useful in biodegradable packaging and biomedical applications (wound dressing and tissue scaffolding).

Volatile Organic Compounds (VOCs) of Endophytic Fungi Growing on Extracts of the Host, Horseradish (Armoracia rusticana)

The interaction between plant defensive metabolites and different plant-associated fungal species is of high interest to many disciplines. Volatile organic compounds (VOCs) are natural products that are easily evaporated under ambient conditions. They play a very important role in inter-species communication of microbes and their hosts. In this study, the VOCs produced by 43 different fungal isolates of endophytic and soil fungi during growth on horseradish root (Armoracia rusticana) extract or malt extract agar were examined, by using headspace-gas chromatography-mass spectrometry (headspace-GC-MS) and a high relative surface agar film as a medium. The proposed technique enabled sensitive detection of several typical VOCs (acetone, methyl acetate, methyl formate, ethyl acetate, methyl butanol isomers, styrene, beta-phellandrene), along with glucosinolate decomposition products, including allyl cyanide and allyl isothiocyanate and other sulfur-containing compounds—carbon disulfide, dimethyl sulfide. The VOC patterns of fungi belonging to Setophoma, Paraphoma, Plectosphaerella, Pyrenochaeta, Volutella, Cadophora, Notophoma, and Curvularia genera were described for the first time. The VOC pattern was significantly different among the isolates. The pattern was indicative of putative myrosinase activity for many tested isolates. On the other hand, endophytes and soil fungi as groups could not be separated by VOC pattern or intensity.

Surface Morphology Formation of Edible Holographic Marker on Potato Starch with Gelatin or Agar Thin Coatings

Edible films and coatings based on biopolymers to protect and extend the shelf life of food and medicine can be functionalized, by applying a holographic marker on the coating surface for marking products or sensing storage conditions. In this work, holographic markers were prepared on the surface of thin biopolymer coatings based on starch, gelatin, agar and also starch/gelatin and starch/agar blends by the nanoimprint method from a film-forming solution. The morphology of the surface of holographic markers using optical microscopy in reflection mode was examined, as well as the reasons for its formation using an analysis of the flow curves of film-forming solutions. It was found that the surface morphology of the marker strongly depends on the composition, consistency index of film-forming solution and miscibility of the components. It was shown that the starch/agar film-forming solution at the ratio of 70/30 wt.% has a low consistency index value of 21.38 Pa·s0.88, compared to 64.56 Pa·s0.67 for pure starch at a drying temperature of 30 °C, and the components are well compatible. Thus, an isotropic morphology of the holographic marker surface was formed and the value of diffraction efficiency of 3% was achieved, compared to 1.5% for the marker made of pure starch. Coatings without holographic markers were analyzed by tensile strength and water contact angle, and their properties are highly dependent on their composition.

PENGEMBANGAN FILM PENDEK BERBASIS KARAKTER PADA ANAK USIA DINI DI TK. MAARIF NU. HASANUDIN, SURABAYA

The development of this short film was held at Maarif NU Foundation School. HASANUDIN, SURABAYA. Short film media is expected to make early childhood more interested in following the play activities and motivation triggered doing good karakter in him. The research objectives are: 1. Develop a character-based short film that is played by early childhood, 2. Discusses the constraints that occur during the development of this character-based short film. Conclusions that can be taken during the process of developing a character-based short film: 1. There is difficulty in preparing the child in the direction of style and dialogue in front of the camera. 2. It takes a long time, and the production cost is great. Conclusions can be drawn after the process of developing a karaker-based short film: 1 Early-age children who use Audio-Visual Media (FILM) are more interested and more motivated to follow lessons, especially in moral and religious values (based on the basis of film, character). 3. There are some obstacles encountered when the media is displayed during the course of learning: a. The use of film media is required to use a closed room because it requires a slightly dark space for the film looks clear. b. Using audio requires a long preparation, starting from preparing the media, c. Requires many supporting media, including Film (mainstream media), Projector, laptop, sound. d. The teacher must be an expert in operating this medium. Pengembangan film pendek ini dilaksanakan di Lembaga PAUD Maarif NU. HASANUDIN, SURABAYA. Media film pendek ini diharapkan membuat anak usia dini semakin tertarik dalam mengikuti kegiatan bermain dan terpicu motivasinya melakukan karaker-karekter baik dalam dirinya. Adapun tujuan penelitian yang ingin diperoleh adalah: 1.Mengembangkan sebuah film pendek berbasis karakter yang dimainkan oleh anak usia dini, 2. Membahas kendala-kendala yang terjadi selama pengembangan film pendek berbasis karakter ini. Kesimpulan yang dapat diambil selama proses pengembangan film pendek berbasis karakter : 1. Terdapat kesulitan dalam mempersiapkan anak dalam pengarahan gaya dan dialog di depan kamera. 2. Memakan waktu yang cukup lama, dan biaya produksi yang besar. Kesimpulan yang dapat diambil setelah proses pengembangan film pendek berbasis karaker: 1 Anak usia dini yang menggunakan Media Audio Visual (FILM) lebih tertarik dan lebih termotivasi untuk mengikuti pelajaran, terutama dalam aspek nilai moral dan agama (sesuai dengan basis dari film,karakter). 3. Ada beberapa kendala yang dihadapi ketika media di ditayangkan sewaktu pembelajaran antara lain: a. Penggunaan media film diharuskan menggunakan ruangan yang tertutup rapat karena memerlukan ruang yang sedikit gelap agar film tampak jelas. b. Mengunakan audio membutuhkan persiapan yang lama, mulai dari mempersiapkan media, c. Memerlukan banyak media pendukung, antara lain Film (media utama), Proyektor, laptop, sound. d. Guru harus ahli dalam mengoperasikan media ini.

INVESTIGATION ON OXYGEN PERMEABILITY AND SURFACE PROPERTIES OF AGAR FILMS

In this work, agar (AG) films have been prepared using the cast method technique. Surface properties such as contact angle (CA) and morphology of the films were carried out. The water contact angle on the surface of agar film was recorded to be 74.91 ±0.35 indicating good hydrophilicity of the surface, which was confirmed by the scanning electron microscope (SEM) image of the AG film. The contact angle was also studied with the variation of time. After making the initial contact on the substrate, the water contact angle on the AG film was found to decrease gradually with time. Studying the oxygen permeability of the agar film showed that the film had an oxygen permeability of about 187 barer.

Polydopamine-Assisted Silver Nanoparticle Self-Assembly on Sericin/Agar Film for Potential Wound Dressing Application

Silver nanoparticles (AgNPs) are extensively applied for their broad-spectrum and excellent antibacterial ability in recent years. Polydopamine (PDA) has great advantages for synthesizing large amounts of AgNPs, as it has multiple sites for silver ion binding and phenolic hydroxyl structure to reduce silver ions to AgNPs. Here, we mixed sericin and agar solution and dried at 65 °C to prepare a sericin (SS)/Agar composite film, and then coated polydopamine (PDA) on the surface of SS/Agar film by soaking SS/Agar film into polydopamine solution, subsequently synthesizing high-density AgNPs with the assistance of PDA to yield antibacterial AgNPs-PDA- SS/Agar film. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) spectra indicated the successful synthesis of high-density AgNPs on the surface of PDA-SS/Agar film. PDA coating and AgNPs modification did not affect the structure of sericin and agar. Furthermore, water contact angle, water absorption and mechanical property analysis showed that AgNPs-PDA-SS/Agar film had excellent hydrophilicity and proper mechanical properties. Inhibition zone and growth curve assays suggested the prepared film had excellent and long-lasting antibacterial ability. In addition, it had excellent cytocompatibility on the fibroblast NIH/3T3 cells. The film shows great potential as a novel kind of wound dressing.

A Novel AgNPs/Sericin/Agar Film with Enhanced Mechanical Property and Antibacterial Capability

Silk sericin is a protein from a silkworm’s cocoon. It has good biocompatibility, hydrophilicity, bioactivity, and biodegradability. However, sericin could not be used in biomedical materials directly because of its frangible characteristic. To develop multifunctional sericin-based materials for biomedical purposes, we prepared a sericin/agar (SS/agar) composite film through the blending of sericin and agar and repetitive freeze-thawing. Then, we synthesized silver nanoparticles (AgNPs) in situ on the surface of the composite film to endow it with antibacterial activity. Water contact angle, swelling and losing ratio, and mechanical properties analysis indicated that the composite film had excellent mechanical property, hydrophilicity, hygroscopicity, and stability. Scanning electron microscopy and X-ray photoelectron spectroscopy analysis confirmed the successful modification of AgNPs on the composite film. X-ray powder diffraction showed the face-centered cubic structures of the AgNPs. This AgNPs modified composite film exhibited an excellent antibacterial capability against Escherichia coli and Staphylococcus aureus. Our study develops a novel AgNPs/sericin/agar composite film with enhanced mechanical performance and an antimicrobial property for potential biomedical applications.

Preparation and Characterization of AgNPs In Situ Synthesis on Polyelectrolyte Membrane Coated Sericin/Agar Film for Antimicrobial Applications

Antibacterial materials are of great importance in preventing bacterial adhesion and reproduction in daily life. Silver nanoparticle (AgNP) is a broad-spectrum antibacterial nanomaterial that has attracted significant attentions for its ability to endow natural materials with antibacterial ability. Silk sericin (SS) has a great advantage for biomaterial application, as it is a natural protein with excellent hydrophilicity and biodegradability. In this study, we prepared AgNPs and polyelectrolyte membrane (PEM) modified SS/Agar films through the layer-by-layer adsorption technique and ultraviolet-assisted AgNPs synthesis method. The film was well characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy. Other properties such as water contact angle, wettability and tensile strength, the release of silver were also studied. The antimicrobial activity of AgNPs-PEM-SS/Agar film was investigated against Escherichia coli and Staphylococcus aureus as the model microorganisms by the inhibition zone and bacterial growth curve assays. The results suggested that the AgNPs-PEM-SS/Agar film had excellent mechanical performance, high hydrophilicity, prominent water absorption ability, as well as outstanding and durable antibacterial activity. Therefore, the prepared novel AgNPs-PEM-SS/Agar composite film is proposed as a potentially favorable antibacterial biomaterial for biomedical applications.