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Alginate and Hydrogel Applications for Wound Dressing
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Dina Fransiska, Ellya Sinurat, Fera Roswita Dewi, Hari Eko Irianto
Dutra et al. (2020) successfully made transparent, soft, flexible, and mechanically resistant film wound dressings. It used 2% papain as the active agent to speed up the healing process. The films were cast using polyvinyl alcohol: calcium alginate mixes with increasing polysaccharide contents (10%, 20%, and 30% v/v). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry analyses were used to determine the thermal properties of the hydrogel. Tensile strength, elasticity modulus, and breakpoint elongation were measured. The effect of calcium alginate concentration on film properties such as weather resistance, swelling capacity, and mechanical properties has been studied. The stability of the papain in the films was indirectly tested using direct contact hemolysis and validated by blood agar diffusion. The XTT (tetrazolium salt XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) technique was used to assess cytotoxicity. The mixtures were miscible in the polymer concentrations tested. Increased calcium alginate content improves the weatherability and swelling properties of wound dressing films. During swelling testing, the mechanical resistance decreased without the films breaking. The films’ hemolytic activity was mostly maintained throughout the study, indicating that papain was stable in the formulations. The films were non-toxic when tested on cells. The results show that PVA and calcium polymers blend can produce an interactive and bioactive wound dressing containing papain.
Microbiological Diagnosis of Bacterial Diseases
Published in Nancy Khardori, Bench to Bedside, 2018
Sarita Mohapatra, Arti Kapil, Nancy Khardori
Wide mouthed, screw capped, leak proof containers are commonly used for the collection of samples such as sputum, urine, stool. Swabs are generally inferior to other methods of specimen collection. The use of swabs in anaerobic infection should be discouraged. Cotton swabs may contain fatty acids, which inhibit the bacterial growth. Similarly, Calcium alginate swabs may release toxic products, which further hamper the growth of the bacteria. Dacron, Rayon or Polyester swabs should be used for better recovery of fastidious organisms. Ability to absorb and release specimen is another important criteria for the selection of swabs. This varies from material to material. Currently, commercially available flocked swabs are preferred over conventional swabs. The brush bristles of flocked swab are better at retaining the specimen. They also possess numerous microscopic folds, which significantly increase the surface and also allow release of specimen more efficiently for further testing.
Conservative treatment
Published in Ken Myers, Paul Hannah, Marcus Cremonese, Lourens Bester, Phil Bekhor, Attilio Cavezzi, Marianne de Maeseneer, Greg Goodman, David Jenkins, Herman Lee, Adrian Lim, David Mitchell, Nick Morrison, Andrew Nicolaides, Hugo Partsch, Tony Penington, Neil Piller, Stefania Roberts, Greg Seeley, Paul Thibault, Steve Yelland, Manual of Venous and Lymphatic Diseases, 2017
Ken Myers, Paul Hannah, Marcus Cremonese, Lourens Bester, Phil Bekhor, Attilio Cavezzi, Marianne de Maeseneer, Greg Goodman, David Jenkins, Herman Lee, Adrian Lim, David Mitchell, Nick Morrison, Andrew Nicolaides, Hugo Partsch, Tony Penington, Neil Piller, Stefania Roberts, Greg Seeley, Paul Thibault, Steve Yelland
Calcium alginate polysaccharide from seaweed (Kaltostat®) forms a gel on the ulcer which provides a moist environment. It reduces pain, can pack cavities, is absorbent for exudative wounds, promotes haemostasis and is low-allergenic. It may require a secondary dressing.
Alginate-based matrix tablets for drug delivery
Published in Expert Opinion on Drug Delivery, 2023
Natalia Veronica, Paul Wan Sia Heng, Celine Valeria Liew
Generally, alginic acid provides more rapid disintegration than calcium alginate. Alginic acid has greater water wicking and swelling force than calcium alginate [20]. The disintegration mechanisms of alginic acid can be attributed to swelling and shape recovery, whereas calcium alginate’s is mainly by shape recovery [16]. Matrix disintegration is often brought about by surface erosion. At 10% calcium alginate or alginic acid, the gel formed had sufficient viscosity to impede water wicking into the tablets [16]. This indicates a critical alginate concentration, above which the disintegrant performance of alginate is undermined. Therefore, while the formation of a viscous gel limits the functionality of alginate as a tablet disintegrant at high concentrations, alginate at non-gelling concentrations is undoubtedly an attractive nature-based disintegrant for the nutraceuticals and health supplement industries.
Design, development and characterization of interpenetrating polymer network hydrogel bead for controlled release of glipizide drug
Published in Drug Development and Industrial Pharmacy, 2022
Kalaiarasan Sellamuthu, Sheela Angappan
Sodium alginate (SAL) is an anionic linear polysaccharide composed of residues of D-mannuronic acid and L-guluronic acid derived from natural origin, via extracting from marine brown seawood. SAL is sodium salt of alginic acid. As the alginates are nontoxic, biocompatible, biodegradable, water-soluble hydrocolloids, it has led to a vast number of valuable applications in the food, cosmetic and biomedical fields. In presence of divalent metal ions like Ca2+ or trivalent ions such as Al3+, the guluronate monomers of one alginate molecule get cross-linked to another alginate molecule of a similar region resulting in an egg box-like structure [7]. Thus, the phenomenon of forming aqueous-insoluble calcium alginate (CAL) gel helps in drug encapsulation and controlling the drug release [8]. However, CAL beads showed poor mechanical stability in the physiological environment [9]. Under these circumstances, the IPN drug delivery system development could help to overcome the CAL gel limitation and to prolong the drug release for a longer period time. IPN hydrogel beads based on sodium alginate polymers are developed with egg albumin or gelatin, Locust bean gum (Madhavi et al.), cellulose polymers [10–12] and polyvinyl alcohol bring about the controlled release of drugs and better mechanical properties [13]. Furthermore, the addition of another polymer with sodium alginate might cause free space for the easy encapsulation of drugs [14].
Underwater posterior nasal neurectomy compared to resection of peripheral branches of posterior nerve in severe allergic rhinitis
Published in Acta Oto-Laryngologica, 2021
Seiichiro Makihara, Mitsuhiro Okano, Syotaro Miyamoto, Kensuke Uraguchi, Munechika Tsumura, Shin Kariya, Mizuo Ando
To prevent severe postoperative nasal bleeding, we did not injure the SPA around the sphenopalatine foramen. Resection of peripheral branches of the posterior nasal nerve in the inferior turbinate is less invasive, but the peripheral branches of the SPA and veins were also resected simultaneously. Humidification and warming of inspired air, mucociliary activity, and removal of particulate material are essential nasal functions that are greatly impaired in disorders such as atrophic rhinitis and empty nose syndrome. Lack of humidification and glandular destruction can lead to mucosal dryness and crusting after turbinate surgery [11]. Resection of the posterior nasal nerve trunk at the sphenopalatine foramen without resecting the SPA has a positive effect on humidification inside the nose. We think that peripheral branches of the posterior nasal nerve do not need to be resected together if the posterior nasal nerve trunk is resected. In this study, two patients in the Underwater group had minor anterior nasal bleeding from the incision of the anterior inferior turbinate when we removed the chitin-coated gauze one day after the surgery. We think the bleeding occurred because the gauze rubbed against the incision. Instead of using chitin-coated gauze, using calcium alginate might decrease the frequency of nasal bleeding. If patients continue irrigation after the surgery, the calcium alginate will be washed out gradually [12]. If there is still calcium alginate in the nasal cavity when the patients visit the hospital about two weeks after the surgery, it will be removed by suctioning.