scholarly journals Highly absorbent hydrogels comprised from interpenetrated networks of alginate–polyurethane for biomedical applications

2021 ◽  
Vol 32 (6) ◽  
Author(s):  
Jesús A. Claudio-Rizo ◽  
Nallely Escobedo-Estrada ◽  
Sara L. Carrillo-Cortes ◽  
Denis A. Cabrera-Munguía ◽  
Tirso E. Flores-Guía ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Degradation Rate ◽  
High Capacity ◽  
Hydrolytic Degradation ◽  
Absorption Capacity ◽  
Amide Bonds ◽  
E Coli ◽  
Swelling Capacity ◽  
And Storage ◽  
Potential Area

AbstractDeveloping new approaches to improve the swelling, degradation rate, and mechanical properties of alginate hydrogels without compromising their biocompatibility for biomedical applications represents a potential area of research. In this work, the generation of interpenetrated networks (IPN) comprised from alginate–polyurethane in an aqueous medium is proposed to design hydrogels with tailored properties for biomedical applications. Aqueous polyurethane (PU) dispersions can crosslink and interpenetrate alginate chains, forming amide bonds that allow the structure and water absorption capacity of these novel hydrogels to be regulated. In this sense, this work focuses on studying the relation of the PU concentration on the properties of these hydrogels. The results indicate that the crosslinking of the alginate with PU generates IPN hydrogels with a crystalline structure characterized by a homogeneous smooth surface with high capacity to absorb water, tailoring the degradation rate, thermal decomposition, and storage module, not altering the native biocompatibility of alginate, providing character to inhibit the growth of E. coli and increasing also its hemocompatibility. The IPN hydrogels that include 20 wt.% of PU exhibit a reticulation index of 46 ± 4%, swelling capacity of 545 ± 13% at 7 days of incubation at physiological pH, resistance to both acidic and neutral hydrolytic degradation, mechanical improvement of 91 ± 1%, and no cytotoxicity for monocytes and fibroblasts growing for up to 72 h of incubation. These results indicate that these novel hydrogels can be used for successful biomedical applications in the design of wound healing dressings.

scholarly journals Physicochemical and Antimicrobial Properties of Cocoa Pod Husk Pectin Intended as a Versatile Pharmaceutical Excipient and Nutraceutical

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Ofosua Adi-Dako ◽  
Kwabena Ofori-Kwakye ◽  
Samuel Frimpong Manso ◽  
Mariam EL Boakye-Gyasi ◽  
Clement Sasu ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Antimicrobial Properties ◽  
Microbiological Quality ◽  
Elemental Content ◽  
Moderate Activity ◽  
Pharmaceutical Excipient ◽  
E Coli ◽  
Swelling Capacity ◽  
Weak Activity ◽  
Cocoa Pod Husk

The physicochemical and antimicrobial properties of cocoa pod husk (CPH) pectin intended as a versatile pharmaceutical excipient and nutraceutical were studied. Properties investigated include pH, moisture content, ash values, swelling index, viscosity, degree of esterification (DE), flow properties, SEM, FTIR, NMR, and elemental content. Antimicrobial screening and determination of MICs against test microorganisms were undertaken using agar diffusion and broth dilution methods, respectively. CPH pectin had a DE of 26.8% and exhibited good physicochemical properties. Pectin had good microbiological quality and exhibited pseudoplastic, shear thinning behaviour, and high swelling capacity in aqueous media. The DE, FTIR, and NMR results were similar to those of previous studies and supported highly acetylated low methoxy pectin. CPH pectin was found to be a rich source of minerals and has potential as a nutraceutical. Pectin showed dose-dependent moderate activity against gram positive and gram negative microorganisms but weak activity against Listeria spp. and A. niger. The MICs of pectin ranged from 0.5 to 4.0 mg/mL, with the highest activity against E. coli and S. aureus (MIC: 0.5–1.0 mg/mL) and the lowest activity against A. niger (MIC: 2.0–4.0 mg/mL). The study has demonstrated that CPH pectin possesses the requisite properties for use as a nutraceutical and functional pharmaceutical excipient.

Synthesis and Properties of Biodegradable Liquid Crystalline Poly(ester-Urethane)s Based on Poly(L-Lactic Acid)

2013 ◽  
Vol 652-654 ◽  
pp. 459-462
Author(s):  
Ya Tong Guo ◽  
Zhu Zheng ◽  
Zhen Qi Hou ◽  
Jie Du
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Lactic Acid ◽  
Physical Properties ◽  
Liquid Crystalline ◽  
Degradation Rate ◽  
Hydrolytic Degradation ◽  
Hexamethylene Diisocyanate ◽  
Solution Polymerization ◽  
Phase Transition Temperatures

A series of biodegradable segmented liquid crystalline poly(ester-urethane)s were prepared by solution polymerization of poly(L-lactic acid) (PLLA), mesogenic diol prepolymer poly(butylene terephthaloyldioxy dibenzoates) (MD), and hexamethylene diisocyanate (HDI). The MD content was varied from 0 to 40 mol% so that the effects of the mesogen content on the thermal and physical properties, and hydrolytic degradation were examined respectively. It was found that introducing mesogens units could increase the thermal stability and the elastic properties, while reduced the phase transition temperatures and the hydrolytic degradation rate.

scholarly journals Self-Crosslinked Ellipsoidal Poly(Tannic Acid) Particles for Bio-Medical Applications

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2429
Author(s):  
Nurettin Sahiner
Keyword(s):  
Tannic Acid ◽  
Hydrolytic Degradation ◽  
Single Step ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenol Content ◽  
Frap Assay ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Trolox Equivalent ◽  
Free Media

Self-crosslinking of Tannic acid (TA) was accomplished to obtain poly(tannic acid) (p(TA)) particles in single step, surfactant free media using sodium periodate (NaIO4) as an oxidizing agent. Almost monodisperse p(TA) particles with 981 ± 76 nm sizes and −22 ± 4 mV zeta potential value with ellipsoidal shape was obtained. Only slight degradation of p(TA) particles with 6.8 ± 0.2% was observed at pH 7.4 in PBS up to 15 days because of the irreversible covalent formation between TA units, suggesting that hydrolytic degradation is independent from the used amounts of oxidation agents. p(TA) particles were found to be non-hemolytic up to 0.5 mg/mL concentration and found not to affect blood clotting mechanism up to 2 mg/mL concentration. Antioxidant activity of p(TA) particles was investigated by total phenol content (TPC), ferric reducing antioxidant potential (FRAP), trolox equivalent antioxidant capacity (TEAC), total flavanoid content (TFC), and Fe (II) chelating activity. p(TA) particles showed strong antioxidant capability in comparison to TA molecules, except FRAP assay. The antibacterial activity of p(TA) particles was investigated by micro-dilution technique on E. coli as Gram‑negative and S. aureus as Gram-positive bacteria and found that p(TA) particles are more effective on S. aureus with over 50% inhibition at 20 mg/mL concentration attained.

scholarly journals Fabrication of a Novel AgBr/Ag2MoO4@InVO4 Composite with Excellent Visible Light Photocatalytic Property for Antibacterial Use

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1541
Author(s):  
Jie Zhang ◽  
Jia Wang ◽  
Qingjun Zhu ◽  
Binbin Zhang ◽  
Huihui Xu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Degradation Rate ◽  
Photocatalytic Property ◽  
Photocatalytic Reaction ◽  
Composite Photocatalyst ◽  
E Coli ◽  
Radical Trapping ◽  
Visible Light Photocatalytic

A novel AgBr/Ag2MoO4@InVO4 composite photocatalyst with different heterojunction structures was successfully constructed by compounding InVO4 with Ag2MoO4 and AgBr. According to the degradation, antibacterial and free radical trapping data, the photocatalytic antibacterial and antifouling activities of AgBr/Ag2MoO4@InVO4 composite were evaluated, and the corresponding photocatalytic reaction mechanism was proposed. Adding AgBr/Ag2MoO4@InVO4 composite, the degradation rate of ciprofloxacin (CIP) achieved 95.5% within 120 min. At the same time, the antibacterial rates of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) achieved 99.99%. The AgBr/Ag2MoO4@InVO4 composite photocatalyst showed promising usage in photocatalytic antibacterial and purification areas.

One-Step Preparation of Competent E. coli: Transformation and Storage of Bacterial Cells in the Same Solution

2021 ◽  
Vol 2021 (11) ◽  
pp. pdb.prot101212 ◽  
Author(s):  
Michael R. Green ◽  
Joseph Sambrook
Keyword(s):  
Escherichia Coli ◽  
Convenient Method ◽  
Plasmid Dna ◽  
Transformation Efficiency ◽  
Bacterial Cells ◽  
E Coli ◽  
One Step ◽  
And Storage

This protocol describes a convenient method for the preparation, use, and storage of competent Escherichia coli. The reported transformation efficiency of this method is ∼5 × 107 transformants/µg of plasmid DNA.

scholarly journals Hydrogel-Silver Nanoparticle Composites for Biomedical Applications

2020 ◽  
Vol 65 (5) ◽  
pp. 446
Author(s):  
O. Nadtoka ◽  
N. Kutsevol ◽  
T. Bezugla ◽  
P. Virych ◽  
A. Naumenko
Keyword(s):  
Silver Nanoparticle ◽  
Biomedical Applications ◽  
Polymer Network ◽  
Cross Linking ◽  
Polyacrylamide Hydrogels ◽  
Photochemical Generation ◽  
Vis Spectroscopy ◽  
Swelling Capacity ◽  
Swelling Studies ◽  
Nanoparticle Composites

Polyacrylamide and dextran-graft-polyacrylamide hydrogels are prepared and used as nanoreactors and networks for the synthesis of silver nanoparticles (AgNPs). Photochemical generation of AgNPs is carried out under UV-irradiation of Ag+ ions in swollen hydrogels of different cross-linking densities. The obtained hydrogels and hydrogel/AgNPs composites are characterized by TEM, FTIR, and UV–Vis spectroscopy. Swelling studies have shown a relationship between the structure of the hydrogels and their ability to swell. It is shown that the presence of AgNPs in the polymer network leads to a decrease of the swelling capacity. An increase in the cross-linking density leads to an expansion of the AgNPs size distribution for both types of hydrogels. All synthesized hydrogel-silver nanoparticle composites have shown a high activity in the growth retardation of Staphylococcus aureus microorganisms.

scholarly journals Improving laboratory control of butter

2019 ◽  
Vol 14 (2) ◽  
pp. 170-178
Author(s):  
Ivan Georgievich Seregin ◽  
Dmitry Vladimirovich Nikitchenko ◽  
Leonid Borisovich Leontiev ◽  
Olga Andreevna Akulich
Keyword(s):  
Milk Fat ◽  
Social Relation ◽  
Storage Conditions ◽  
Hot Water ◽  
Chain Stores ◽  
E Coli ◽  
Safety Requirements ◽  
Laboratory Control ◽  
The Social ◽  
And Storage

The work is devoted to the improvement of laboratory control of cow butter, which is sold in the chain stores and markets. The social relation of buyers to butter, its range in various retailers are studied, and samples of the butter, acquired in chain stores and markets of Moscow and Vladimir, are investigated. During microbiological studies, the presence of E. coli in the butter “Krestianskoe” was established, which does not meet the safety requirements of this product. In addition, in this butter was revealed a reduced content of milk fat 71.5% instead of 72.5%. Butter “Shokoladnoe” of the “Krestianskoe” trademark had only 60% of fat content, instead of the declared 62%. The packaging of this oil is marked with a distorted label according to the shelf life and storage conditions, which indicates information falsification. There is a mismatch in selected samples with the requirements of GOST and the stated indicators, which indicates the need to develop additional methods for identifying various fakes in butter. It was determined that by melting butter in hot water, by microscopying a product using a compressor or by irradiating the surface of butter with UV rays, it is possible to quickly and reliably identify some of its falsifications.

scholarly journals KEBERADAAN MIKROBA PADA BAKSO IKAN ASAP CAIR, YANG DIKEMAS DALAM RETORTABLE POUCH, DIPASTEURISASI DAN DISIMPAN PADA TEMPERATUR RUANG

2016 ◽  
Vol 4 (2) ◽  
pp. 85
Author(s):  
Margani Luyuani Rohana ◽  
Siegfried Berhimpon ◽  
Joyce CV Palenewen
Keyword(s):  
Shelf Life ◽  
Water Content ◽  
Experimental Method ◽  
Room Temperature ◽  
Plate Count ◽  
E Coli ◽  
Existing Problems ◽  
Liquid Smoke ◽  
Total Plate Count ◽  
And Storage

A research has been done to assess the presence of microbes and the shelf life of fish balls dipped in liquid smoke, packed in retortable pouch, pasteurized, and stored at room temperature. The method used in this research is an experimental method that revealed the facts based on existing problems through hypothesis testing. Parameters assessed are Total Plate Count (TPC), total Salmonella, total coliforms and E. coli, total vibrio, water content, and pH. Fish balls were pasteurized in 85ºC and stored in room temperature for 0, 3, 6, and 9 days, and were pasteurized at 100°C and storage in room temperature for 0, 9, 18, and 27 days. The results shown that all pathogen were negative, but based on Indonesian standard (SNI 01-7266-1-2006) especially TPC value, fish balls were packaged in retortable pouch and without pasteurized is no longer acceptable for consumption after 3 days of storage, and fish balls were packaged in retortable pouch and pasteurized at 85ºC no longer acceptable for consumed after 6 days of storage. While the fish balls are packaged in retortable pouch and pasteurized at 100°C is no longer acceptable for consumed after 18 days of storage.Keyword: Retortable Pouch, Pasteurization, Pathogens.  Penelitian ini bertujuan untuk mengetahui keberadaan mikroba dan daya awet bakso ikan yang direndam dalam asap cair dan dikemas dalam Retortable pouch, dipasteurisasi, dan disimpan pada temperatur ruang. Metode yang digunakan dalam penelitian ini adalah metode eksperimen untuk menguji hipotesa. Parameter yang diamati yaitu Angka Lempeng Total (ALT), Salmonella, total koliform dan E.coli, total vibrio, analisa kadar air, dan nilai pH. Bakso ikan asap cair yang dipasteurisasi pada 85ºC, disimpan pada temperatur ruang selama 0, 3, 6, dan 9 hari, dan yang dipasteurisasi pada 100ºC, disimpan pada temperatur ruang selama 0,9,18, dan 27 hari. Hasil penelitian menunjukkan bahwa bakso ikan yang dikemas dalam Retortable pouch, tanpa dipasteurisasi sudah tidak layak lagi untuk dikonsumsi setelah penyimpanan 3 hari, dan bakso ikan yang dikemas dalam Retortable pouch dan dipasteurisasi pada 85ºC sudah tidak layak lagi untuk dikonsumsi setelah penyimpanan 6 hari. Bakso ikan yang dikemas dalam Retortable pouch, dan dipasteurisasi pada 100ºC nanti tidak layak lagi dikonsumsi setelah penyimpanan 18 hari.Kata Kunci: Kemasan Retortable Pouch, Pasteurisasi, Patogen.

scholarly journals Quality Characteristics of Biscuits Produced from Composite Flour of Sweet Potato and Cashew Nut Flour Blends

2020 ◽  
pp. 11-22
Author(s):  
O. O. Tanko ◽  
T. O. Hussaina ◽  
N. S. Donaldben
Keyword(s):  
Sweet Potato ◽  
Absorption Capacity ◽  
Composite Flour ◽  
Crude Fibre ◽  
Overall Acceptability ◽  
Spread Ratio ◽  
Cashew Nut ◽  
Significant Difference ◽  
Swelling Capacity ◽  
Flour Blends

The research is aimed at adding value to sweet potato based biscuits using underutilized crops such as cashew nuts. The objective of the study was to add value to sweet potato based biscuits, the sweet potato was processed into flour; while the cashew nuts was unroasted cashew nuts were sorted to remove the stones, dirt’s and unwholesome cashew nuts, roasted, shelled, dried, peeled and processed into flour and sieved. The cashew nuts flour was substituted at 20, 30, 40 and 50% into sweet potato flour to produce sweet potato and cashew nuts composite flour were  used for the production of biscuits. Functional, proximate composition of the biscuits, physical and sensory properties of composite biscuits were determined. Significance difference (P<0.05) was observed Bulk density, water absorption capacity, oil absorption capacity, swelling capacity, emulsion activity, foaming stability and gelatinization temperature increased from 0.62 to 0.73 g/cm3, 1.31 to 1.81 g/g, 2.10 to 2.22 g/g, 6.42 to 7.18 ml, 59.71 to 60.51%, 6.19 to 6.43% and 68.20 to 72.10ºC, respectively with an increase in the addition of cashew nuts flour. The crude protein, crude fat, crude fibre and ash increase from 14.65 to 18.31%, 7.88 to 10.21%, 3.21 to 3.51% and 4.10 to 4.76% respectively; while the moisture and carbohydrate content of the biscuits decreased from 13.77 to 13.31% and 56.39 to 49.89%, respectively with increase in the addition of the cashew nuts flour. The physical properties of the composite biscuits such as the weight, thickness, diameter and spread ratio ranged from 16.09 to 17.45 g, 10.87 to 10.96 mm, 38.94 to 40.02 mm and 3.56 to 3.60 respectively. The average means scores for the appearance, crispness, taste, aroma and overall acceptability increase were observed. There was a significant difference (p<0.05) in the appearance, taste and aroma while there was no significant difference (p>0.05) in the crispness and overall acceptability.

scholarly journals Effect of natural preservatives on the organoleptic characteristics and storage stability of smoked Heterotis niloticus

Agro-Science ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 31-35
Author(s):  
K.E. Amuneke ◽  
O.R. Oguntade ◽  
F.C. Ikeogu ◽  
U.A. Nomeh
Keyword(s):  
Shelf Life ◽  
Storage Stability ◽  
Control Sample ◽  
Muscle Quality ◽  
Value Addition ◽  
E Coli ◽  
Organoleptic Characteristics ◽  
Microbial Analysis ◽  
Natural Preservatives ◽  
And Storage

Improvement of consumer’s palatability of Heterotis niloticus was investigated by value addition with natural spices and salt to improve its  palatability and shelf-life. The major problem of H. niloticus is its poor taste, hence low demand and poor consumer’s acceptability which affects the market value. The objective of this study was to improve the palatability and shelf-life of H. niloticus using selected natural spices. Heterotis niloticus, procured and treated with natural spices and salt were allowed to drain for one hour, subjected to charcoal fired smoking kiln for 12 hours, cooled and stored for 8 weeks at ambient temperature before microbial analysis. The result showed that treatment 1 had the best quality (37.7%), followed by control sample (34.7%), and treatment 2 (28.9%), while the least was treatment 3 (21.6%). Microbial analysis shows that no Salmonella, Coliforms and E. coli were detected from the samples after smoking. Staphylococcus aureus count ranged from 2 × 102 to 9 × 102 but it was not detected in treatment 1. Improvement of the consumers’ palatability of H. niloticus and improved storage stability by spicing methods improved the  poor taste of H. niloticus which has been discriminated despites excellent muscle quality. Key words: Heterotis niloticus, organoleptic, spicing, microbial analysis

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