Alginate microsphere fabrication using bipolar wave-based drop-on-demand jetting

Abstract

Scale-up microsphere fabrication with controllable microsphere size has always been an exciting manufacturing challenge. The objective of this study is to experimentally study the effects of material properties and operating conditions on the formability of alginate microspheres and the microsphere size during drop-on-demand (DOD)-based single nozzle jetting. Alginate microspheres have been fabricated using bipolar wave-based drop-on-demand jetting, and its formability and size have been studied especially as a function of sodium alginate and calcium chloride concentrations, voltage rise/fall times, dwell and echo times, excitation voltage amplitudes, and frequency. It is found that 1) the formability is sensitive to the sodium alginate and calcium chloride concentrations, dwell and echo voltages, and voltage dwell time; and the formability decreases with the sodium alginate concentration but increases with the calcium chloride concentration, dwell and echo voltages, and voltage dwell time; 2) the size is not sensitive to the sodium alginate and calcium chloride concentrations but increases first with the dwell time and then decreases; and 3) the size increases with the dwell and absolute echo voltage amplitudes.

Effects of fluid properties and laser fluence on jet formation during laser direct writing of glycerol solution

“…During orifice-based direct writing, fluid jets are first ejected from an orifice and then broken into droplets with, or without, satellite droplets. 14,15 The droplets that are generated combine to form various structures in a controllable manner. During laserassisted orifice-free direct writing such as LIFT, the material transfer and deposition can be due to either ejected droplets 7,16 or the contact between formed long, thin jet and the receiving substrate 17,18 depending on the direct writing height and the material properties.…”

Inkjet‐Printed Alginate Microspheres as Additional Drug Carriers for Injectable Hydrogels

“…This is consistent with the literature where the generation of particles improves with CaCl 2 concentration. 18 In this study, a lower alginate concentration (0.5% w/v) was used as compared to studies also printing alginate. This was due to the higher chances of clogging at the nozzle when higher concentrations (>0.5% w/v) were used.…”

“…17,18 On the other hand, alginate is known for its cell compatibility and good stability. 19 Therefore, the objective of this study was to evaluate the feasibility of incorporating alginate hydrogel microspheres into the thermosensitive gel (Lutrol F127) for sustained intratympanic delivery of FITC-dextran as the model drug.…”

A comprehensive review on droplet-based bioprinting: Past, present and future

“…The volume of ejected droplets is mediated by several operating parameters such as the bioink material characteristics, the printhead geometry (orifice diameter) and its actuation voltage pulse characteristics [23,32,36,43,46,71,82,83]. For example, the width of each M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 13 coalesced line in Fig.…”