Production of letrozole-loaded alginate oxide-gelatin microgels using microfluidic systems for drug delivery applications.

Microfluidic systems are capable of producing microgels with a monodisperse size distribution and a spherical shape due to their laminar flow and superior flow. A significant challenge in producing these drug-carrying microgels is simultaneous drug loading into microgels. Various factors such as the type of polymer, the type of drug, the volume ratio of the drug to the polymer, and the geometry of the microfluidic system used to generate microgels can effectively address these challenges. The overall goal of this study was to produce mono-disperse drug-carrying microgels capable of controlled drug release. To achieve this goal, this study used a stream-focused microfluidic chip containing a coating current to prevent chip clogging. Alginate oxide was synthesized with a 30 % oxidation percentage. Alginate oxide, gelatin, and compositions of them with volume ratios of 50-50, 70-30, and 30-70, by determining their appropriate weight percentage, were used for the controlled release of letrozole. The properties of the produced microgels were measured through various tests such as drug release test, loading percentage, SEM, FTIR, swelling ratio, and dimensional stability. It was found that microgels made of a combination of alginate oxide-gelatin with volume ratios of 70-30 had a good swelling ratio and structural stability. The drug loading percentages for alginate, alginate oxide, and alginate oxide-gelatin with volume ratios of 50-50 and 30-70, respectively, were 56 %, 68 %, and 66 %, 61 % and the alginate oxide-gelatin with a volume ratio of 70-30 compared to other samples had over 70 % drug loading percentages. Furthermore, samples of alginate, alginate oxide, and alginate oxide-gelatin with volume ratios of 50-50 and 30-70 had 94 %, 63 %, 56 %, and 68 % drug release in 13 days, respectively. However, alginate oxide-gelatin with a volume ratio of 70-30 had a release rate of about 50 % in 13 days, which is a more controlled release for letrozole compared to the volume ratios of 50-50 and 30-70. Examining the drug release profile, it was concluded that drug release follows the Higuchi model and therefore follows Fick's first law of diffusion. It can be concluded that the combination of alginate oxide-gelatin produces more suitable microgels than alginate and alginate oxide for the controlled-release of letrozole. A comparison of microgels of alginate oxide and gelatin with volume ratios of 50-50 and 70-30 had better results for the cytotoxicity study compared to other samples.

Microfluidic synthesis of lipid-based nanoparticles for drug delivery: recent advances and opportunities.

Microfluidic technologies are revolutionizing the synthesis of nanoscale lipid particles and enabling new opportunities for the production of lipid-based nanomedicines. By harnessing the benefits of microfluidics for controlling diffusive and advective transport within microfabricated flow cells, microfluidic platforms enable unique capabilities for lipid nanoparticle synthesis with precise and tunable control over nanoparticle properties. Here we present an assessment of the current state of microfluidic technologies for lipid-based nanoparticle and nanomedicine production. Microfluidic techniques are discussed in the context of conventional production methods, with an emphasis on the capabilities of microfluidic systems for controlling nanoparticle size and size distribution. Challenges and opportunities associated with the scaling of manufacturing throughput are discussed, together with an overview of emerging microfluidic methods for lipid nanomedicine post-processing. The impact of additive manufacturing on current and future microfluidic platforms is also considered.

A New Detection Chamber Design on Centrifugal Microfluidic Platform to Measure Hemoglobin of Whole Blood.

Undoubtedly, microfluidics has been a focal point of interdisciplinary science during the last two decades, resulting in many developments in this area. Centrifugal microfluidic platforms have good potential for use in point-of-care devices because they take advantage of some intrinsic forces, most notably centrifugal force, which obviates the need to any external driving forces. Herein, we introduce a newly designed detection chamber for use on microfluidic discs that can be employed as an absorbance readout step in cases where the final solution has a very low viscosity and surface tension. In such situations, our chamber easily eliminates the air bubbles from the final solution without any interruption. One microfluidic disc for measuring the hemoglobin concentration was designed and constructed to verify the correct functioning of this detection chamber. This disc measured the hemoglobin concentration of the blood samples via the HiCN method. Then, the hemoglobin concentration of 11 blood samples was quantified and compared with the clinic's data using the hemoglobin measurement disc, which included four hemoglobin measurement sets, and each set contained two inlets for the blood sample and the reagent, one two-part mixing chamber, and one bubble-free detection chamber. The measured values of the disc had good linearity and conformity compared with the clinic's data, and there were no air bubbles in the detection step. In this study, the standard deviation and the turnaround time were ± 0.51 g/dL and 68 s, respectively.