scholarly journals An Additively Manufactured Sample Holder to Measure the Controlled Release of Vancomycin from Collagen Laminates

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1668
Author(s):  
Michelle Fiona Kilb ◽  
Yannik Moos ◽  
Stefanie Eckes ◽  
Joy Braun ◽  
Ulrike Ritz ◽  
...  
Keyword(s):  
Controlled Release ◽  
Green Light ◽  
Sample Holder ◽  
Proof Of Concept ◽  
Lower Cavity ◽  
Photochemical Crosslinking ◽  
High Concentrations ◽  
Antibiotic Release ◽  
Covalently Linked ◽  
Healing Processes

The controlled release of antibiotics prevents the spread of pathogens and thereby improves healing processes in regenerative medicine. However, high concentrations may interfere with healing processes. It is therefore advantageous to use biodegradable materials for a controlled release. In particular, multilayer materials enable differential release at different surfaces. For this purpose, collagen sheets of different properties can be bonded by photochemical crosslinking. Here, we present the development and application of an easily accessible, additively manufactured sample holder to study the controlled release of vancomycin from modularly assembled collagen laminates in two directions. As proof-of-concept, we show that laminates of collagen sheets covalently linked by rose bengal and green light crosslinking (RGX) can be tightly inserted into the device without leakage from the upper to lower cavity. We used this sample holder to detect the release of vancomycin from symmetrically and asymmetrically loaded two-layer and three-layer collagen laminates into the upper and lower cavity of the sample holder. We show that these collagen laminates are characterized by a collagen type-dependent vancomycin release, enabling the control of antibiotic release profiles as well as the direction of antibiotic release.

scholarly journals MICROENCAPSULATION of grapefruit oil with sodium alginate by gelation and ionic extrusion: optimization and modeling of crosslinking and study of controlled release kinetics.

2020 ◽  
pp. 41-61
Author(s):  
Liliana Mariel Cáceres ◽  
Gustavo Adolfo Velasco ◽  
Eliana Paola Dagnino ◽  
Ester R Chamorro
Keyword(s):  
Controlled Release ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Release Kinetics ◽  
Antimicrobial Properties ◽  
Chloride Concentration ◽  
Crosslinking Process ◽  
Elovich Equation ◽  
Pharmaceutical Industries ◽  
High Concentrations

Essential grapefruit oil with high concentrations of limonene is used in food, cosmetic and pharmaceutical industries due to its antimicrobial properties, fragrance, and flavor. To facilitate its manipulation and protect it from adverse environmental factors, the microencapsulation is used. The objective of this work was to optimize the microencapsulation process of grapefruit oil using external ionic gelation coupled to extrusion with sodium alginate and calcium chloride. We achieved the best encapsulation conditions with calcium chloride concentration at 7.4% w/v and a crosslinking time of 58 minutes, obtaining a yield of 62% and an efficiency of 100% with an oil loading capacity of 10% w/w. The chemical adsorption of calcium as well during the crosslinking process was studied, observing a significant fit with the Elovich equation. And an adjustment of the controlled release of the oil was obtained to the empirical kinetic model of Korsmeyer and Peppas.

Biomass deflocculation and process disturbances exerted by phenol induced transient load conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 105-112 ◽  
Author(s):  
N. I. Galil ◽  
A. Schwartz-Mittelman ◽  
O. Saroussi-Zohar
Keyword(s):  
Controlled Release ◽  
Phenol Removal ◽  
Transient Load ◽  
Uptake Rates ◽  
Suspended Biomass ◽  
Treatment Facilities ◽  
Phenolic Wastewater ◽  
High Concentrations ◽  
Process Disturbances ◽  
Load Conditions

Turbidity and relatively high concentrations of polysaccharides (biopolymers), indicating deflocculation of suspended biomass, could be observed as a result of phenol supplied in transient load conditions. The importance of preliminary acclimation could be observed in terms of the phenol removal rates at relatively low transient loading of phenol, up to 500 mg/l. As shock intensity increased to 1,000 and 1,500 mg/l, the acclimated reactors did not show relevant differences when compared to either partially acclimated or on-acclimated reactors. Transient load conditions created by phenol caused immediate reduction of the oxygen uptake rates and affected biomass respiration. Preliminary acclimation of the biomass indicated possible improvements of these influences, especially for phenol loads of up to 500 mg/l. The period following the application of phenol transient load was characterized by symptoms which could indicate that sorption-desorption mechanisms are involved by biomass, in addition to biodegradation. Preliminary collection and temporary storage of concentrated phenolic wastewater streams followed by gradually controlled release to the treatment facilities would provide reasonable solutions for avoiding biomass deflocculation and process disturbances caused by transient load conditions.

scholarly journals Mechanical Characterization of Rose Bengal and Green Light Crosslinked Collagen Scaffolds for Regenerative Medicine

2021 ◽  
Author(s):  
Joy Braun ◽  
Stefanie Eckes ◽  
Michelle Fiona Kilb ◽  
Dirk Fischer ◽  
Claudia Eßbach ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rose Bengal ◽  
Mechanical Stability ◽  
Green Light ◽  
Tensile Tests ◽  
Linear Increase ◽  
Cell Contact ◽  
Collagen Scaffolds ◽  
Photochemical Crosslinking ◽  
The Impact

Abstract Collagen is one of the most important biomaterials for tissue engineering approaches. Despite its excellent biocompatibility, it shows the non-negligible disadvantage of poor mechanical stability. Photochemical crosslinking with rose bengal and green light (RGX) is an appropriate method to improve this property. The development of collagen laminates is helpful for further adjustment of the mechanical properties as well as the controlled release of incorporated substances. In this study, we investigate the impact of crosslinking and layering of two different collagen scaffolds on the swelling behavior and mechanical behavior in micro tensile tests to obtain information on its wearing comfort (stiffness, strength and ductility). The mechanical stability of the collagen material after degradation due to cell contact is examined using thickness measurements. There is no linear increase or decrease due to layering homologous laminates. Unexpectedly, a decrease in elongation at break, Younǵs modulus and ultimate tensile strength is measured when the untreated monolayer is compared to the crosslinked one. Furthermore we can detect a connection between stability and cell proliferation. The results show that with variation in number and type of layers, collagen scaffolds with tailored mechanical properties can be produced. Such a multi-layered structure enables the release of biomolecules into inner or outer layers for biomedical applications.

scholarly journals New Drug Delivery Systems Concept in Anaesthesia and Intensive Care—Controlled Release of Active Compounds

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Tiberiu Bratu ◽  
Anca Dinu ◽  
Mihai Sandesc ◽  
Sonia Elena Popovici ◽  
Razvan Gabriel Dragoi ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Controlled Release ◽  
Active Substance ◽  
Drug Delivery Systems ◽  
Pharmaceutical Research ◽  
Innovative Method ◽  
Other Substances ◽  
Antibiotic Release ◽  
Active Substances

AbstractWith time, medical and pharmaceutical research has advanced significantly. However, one of the major issues is how to administer the active substance. Among these, it counts over- or under-dosage of the active substance, low re­sponse to treatment, or increased clinical risk of the patient. An innovative method able to avoid these obstacles is represented by controlled release systems for active substances. The interest for these systems came with allowing encapsulation in the antibiotic release matrices, local anesthetics, protein or other substances. Moreover, a number of such vehicles are now available to release controlled substances used predominantly in the anesthesia and intensive care unit.

Stability and controlled antibiotic release from thin films embedded with antibiotic loaded mesoporous silica nanoparticles

RSC Advances ◽  
2015 ◽  
Vol 5 (130) ◽  
pp. 107839-107846 ◽  
Author(s):  
Tasnuva Tamanna ◽  
Jurgen B. Bulitta ◽  
Cornelia B. Landersdorfer ◽  
Veronica Cashin ◽  
Aimin Yu
Keyword(s):  
Thin Films ◽  
Controlled Release ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Release Profile ◽  
Antibiotic Release ◽  
Excellent Stability

Thin films incorporated with gentamicin loaded mesoporous silica nanoparticles exhibit excellent stability and controlled release profile of the encapsulated antibiotic.

scholarly journals Controlled Release of Retinol in Cationic Co-Polymeric Nanoparticles for Topical Application

Cosmetics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 29 ◽  
Author(s):  
Fabien Goudon ◽  
Yohann Clément ◽  
Lionel Ripoll
Keyword(s):  
Controlled Release ◽  
Kinetic Study ◽  
Active Ingredient ◽  
High Efficiency ◽  
Polymeric Nanoparticles ◽  
Cationic Polymer ◽  
Narrow Size Distribution ◽  
Extreme Sensitivity ◽  
High Concentrations ◽  
Skin Conditions

Retinol is a compound used in many skin care formulations to act against skin conditions like acne, wrinkles, psoriasis, and ichthyosis. While retinol is used as an active ingredient, its efficacy is limited by an extreme sensitivity to light and temperature. Retinol can also generate toxicity at high concentrations. Microencapsulation is an alternative method to help overcome these issues. In this study, we develop a new encapsulation of retinol by solvent evaporation using a cationic polymer. We show that our particles have a narrow size distribution (350 nm), can encapsulate retinol with high efficiency, and protect it from oxidation for at least eight weeks. Finally, to demonstrate that the release of retinol from the particles can be controlled, we performed a kinetic study and showed that the particle releases the drug during 18 h.

scholarly journals An innovative method for rapid detection of urinary oxalate in goats with urolithiasis

2021 ◽  
Author(s):  
Tina Esfandiary ◽  
Suraj Patel ◽  
Arun Wanchoo ◽  
Alexandria Voigt ◽  
Samuel Tao ◽  
...  
Keyword(s):  
Kidney Stone ◽  
Point Of Care ◽  
Stone Disease ◽  
Future Application ◽  
Care Practice ◽  
Urinary Oxalate ◽  
Proof Of Concept ◽  
Innovative Method ◽  
Stone Prevention ◽  
High Concentrations

Abstract Background: Oxalate is a natural and abundant metabolic by-product; as a highly oxidized organic compound with powerful chelating activity, in high concentrations it can cause morbidity and mortality in both animals and humans. Elevated levels in urine (i.e., hyperoxaluria) have been found to correlate with several human diseases, especially urolithiasis or kidney stone disease (KSD)- a disease also prevalent in goats. Current methods for measuring oxalate are highly technical, cumbersome, and time-consuming, which often forces clinics to utilize expensive diagnostic laboratories. Therefore, in this study, we designed an innovative device, Oxalometer, to measure urinary oxalate in goats. Results: The results indicate that the Oxalometer performed as accurately as the standard commercially available test. The Oxalometer was able to measure higher levels of urinary oxalate in goats with urolithiasis compared to non-urolithiasis goats. The data demonstrate the accuracy and sensitivity of the Oxalometer. Conclusions: This proof-of-concept study supports the future application of the device in determining on-the-spot oxalate levels in patients and brings kidney stone prevention to point-of-care practice for ruminants.

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