Effect of Technological Factors on the Extraction of Polymeric Condensed Tannins from Acacia Species.

The aim of this research work was to investigate the influence of parameters such as particle size, mass/solvent ratio, temperature and spray drying on the tannin extraction process in order to develop cost-effective methods with better environmental and structural performance. The pods of Acacia nilotica ssp. tomentosa (ANT) were fractionated into three fractions, coarse fraction (C) (>2 mm), medium fraction (M) (1-2 mm), and fine fraction (F) < 1 mµ), and extracted with different water-to-pod ratios (2:1, 4:1 and 6:1) at different temperatures (30, 50 and 70 °C). The best results were scaled up using the three fractions of ANT, its bark and the bark of Acacia seyal var. seyal (ASS). Part of their extract was spray dried. The tannin content and total polyphenolic materials were evaluated using standard methods. Their adhesives were tested for their tensile strength. Tannins of ASS were characterized by 13C NMR and MALDI-TOF. The results revealed that the fine fraction (F) gave the highest percentage of tannins in both small and scaled-up experiments. The results of the tensile strength conformed to the European standard. The 13C NMR spectra of ANT and ASS showed that the bark contained condensed tannins mainly consisting of procyanidins/prodelphinidin of 70%/30% and 60%/40%, respectively. MALDI-TOF spectra confirmed the results obtained by 13C NMR and detailed the presence of flavonoid monomers and oligomers, some of which were linked to short carbohydrate monomers or dimers.

Optical biosensors - Illuminating the path to personalized drug dosing.

Optical biosensors are low-cost, sensitive and portable devices that are poised to revolutionize the medical industry. Healthcare monitoring has already been transformed by such devices, with notable recent applications including heart rate monitoring in smartwatches and COVID-19 lateral flow diagnostic test kits. The commercial success and impact of existing optical sensors has galvanized research in expanding its application in numerous disciplines. Drug detection and monitoring seeks to benefit from the fast-approaching wave of optical biosensors, with diverse applications ranging from illicit drug testing, clinical trials, monitoring in advanced drug delivery systems and personalized drug dosing. The latter has the potential to significantly improve patients' lives by minimizing toxicity and maximizing efficacy. To achieve this, the patient's serum drug levels must be frequently measured. Yet, the current method of obtaining such information, namely therapeutic drug monitoring (TDM), is not routinely practiced as it is invasive, expensive, time-consuming and skilled labor-intensive. Certainly, optical sensors possess the capabilities to challenge this convention. This review explores the current state of optical biosensors in personalized dosing with special emphasis on TDM, and provides an appraisal on recent strategies. The strengths and challenges of optical biosensors are critically evaluated, before concluding with perspectives on the future direction of these sensors.

Electrochemical biosensors: a nexus for precision medicine.

Precision medicine is a field with huge potential for improving a patient's quality of life, wherein therapeutic drug monitoring (TDM) can provide actionable insights. More importantly, incorrect drug dose is a common contributor to medical errors. However, current TDM practice is time-consuming and expensive, and requires specialised technicians. One solution is to use electrochemical biosensors (ECBs), which are inexpensive, portable, and highly sensitive. In this review, we explore the potential for ECBs as a technology for on-demand drug monitoring, including microneedles, continuous monitoring, synthetic biorecognition elements, and multi-material electrodes. We also highlight emerging strategies to achieve continuous drug monitoring, and conclude by appraising recent developments and providing an outlook for the field.

Rheological and Mechanical Investigation into the Effect of Different Molecular Weight Poly(ethylene glycol)s on Polycaprolactone-Ciprofloxacin Filaments.

Fused deposition fabrication (FDF) three-dimensional printing is a potentially transformative technology for fabricating pharmaceuticals. The state-of-the-art technology is still in its infancy and requires a concerted effort to realize its potential. One aspect includes the processing parameters of FDF and the effect of formulation thereto, which, to date, have not been thoroughly investigated. To progress understanding, the effect of different molecular weight poly(ethylene glycol)s (PEG) on polycaprolactone (PCL) loaded with ciprofloxacin (CIP) was investigated. A rheometer was used, and adapted accordingly, to analyze three processing aspects pertaining to FDF: viscosity, solidification, and adhesion. The results revealed that both CIP and PEG affected all three processing parameters. The salient findings were that the ternary blend with 10% w/w PEG 8000 exhibited rheological and adhesive properties ideal for FDF, as it provided a desirably shear-thinning filament that solidified rapidly, and improved the adhesion strength, in comparison to both the PCL-CIP binary blend and other ternary blends. In contrast, the ternary blend with 15% w/w PEG 200 was unfavorable; despite having a greater plasticizing effect, whereby the viscosity was markedly reduced, the sample provided no benefit to the solidification behavior of PCL-CIP and, in addition, failed to display adhesive behavior, which is a necessity for a successful print in FDF. The original findings herein set the precedent that the effect of drug and PEG on FDF processing should be considered beyond solely modifying the viscosity.

Incorporation of HA into porous titanium to form Ti-HA biocomposite foams.

Ti foams are advanced materials with great potential for biomedical applications as they can promote bone ingrowth, cell migration and attachment through providing interconnected porous channels that allow the penetration of the bone-forming cells and provide them with anchorage sites. However, Ti is a bio-inert material and thus only mechanical integration is achieved between the porous implant and the surrounding tissue, not the chemical integration which would be desirable. In this work particles of a biologically active material (Hydroxyapatite, HA) are blended with titanium powder, and used to produce Ti foams through the use of Metal Injection Moulding (MIM) in combination with a space holder. This produces titanium foams with incorporated HA, potentially inducing more favourable bone response to an implant from the surrounding tissue and improving the osseointegration of the Ti foams. To be able to do this, samples need to show sufficient mechanical and biocompatibility properties, and the foams produced were assessed for their mechanical behaviour and in vitro biological response. It was found that the incorporation of high levels of HA into the Ti foams induces brittleness in the structure and reduces the load bearing ability of the titanium foams as the chemical interaction between Ti and HA results in weak ceramic phases. However, adding small amounts of HA (about 2 vol%) was found to increase the yield strength of the Ti foams by 61% from 31.6 MPa to 50.9 MPa. Biological tests were also carried out in order to investigate the suitability of the foams for biomedical applications. It was found that Ti foams both with and without HA (at the 2 vol% addition level) support calcium and collagen production and have a good level of biocompatibility, with no significant difference observed between samples with and without the HA addition.