Droplet Microfluidic Optimisation Using Micropipette Characterisation of Bio-Instructive Polymeric Surfactants

Droplet microfluidics can produce highly tailored microparticles whilst retaining monodispersity. However, these systems often require lengthy optimisation, commonly based on a trial-and-error approach, particularly when using bio-instructive, polymeric surfactants. Here, micropipette manipulation methods were used to optimise the concentration of bespoke polymeric surfactants to produce biodegradable (poly(d,l-lactic acid) (PDLLA)) microparticles with unique, bio-instructive surface chemistries. The effect of these three-dimensional surfactants on the interfacial tension of the system was analysed. It was determined that to provide adequate stabilisation, a low level (0.1% (w/v)) of poly(vinyl acetate-co-alcohol) (PVA) was required. Optimisation of the PVA concentration was informed by micropipette manipulation. As a result, successful, monodisperse particles were produced that maintained the desired bio-instructive surface chemistry.

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Novel biodegradable poly(propylene fumarate)-co-poly(l-lactic acid) porous scaffolds fabricated by phase separation for tissue engineering applications

RSC Advances ◽

10.1039/c5ra00508f ◽

2015 ◽

Vol 5 (27) ◽

pp. 21301-21309 ◽

Cited By ~ 28

Author(s):

Xifeng Liu ◽

A. Lee Miller II ◽

Brian E. Waletzki ◽

Michael J. Yaszemski ◽

Lichun Lu

Keyword(s):

Lactic Acid ◽

Phase Separation ◽

Three Dimensional ◽

Porous Scaffolds ◽

Porous Structures ◽

Polymer Scaffolds ◽

Thermally Induced Phase Separation ◽

Thermally Induced ◽

Biodegradable Poly ◽

Poly Propylene

Three-dimensional polymer scaffolds with interconnected porous structures were fabricated by thermally induced phase separation of novel biodegradable poly(propylene fumarate)-co-poly(l-lactic acid).

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Three-dimensional printed biodegradable poly(l-lactic acid)/(poly(d-lactic acid) scaffold as an intervention of biomedical substitute

Polymer-Plastics Technology and Materials ◽

10.1080/25740881.2021.1876879 ◽

2021 ◽

pp. 1-11

Author(s):

Mohamad Amin Jumat ◽

Pascale Chevallier ◽

Diego Mantovani ◽

Francesco Copes ◽

Saiful Izwan Abd Razak ◽

...

Keyword(s):

Lactic Acid ◽

Three Dimensional ◽

Biodegradable Poly

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Three-dimensional crimped biodegradable poly(lactic acid) fibers prepared via melt spinning and controlled structural reorganization

RSC Advances ◽

10.1039/d0ra08681a ◽

2020 ◽

Vol 10 (70) ◽

pp. 42890-42896

Author(s):

Bo Yang ◽

Rui Wang ◽

Zhenfeng Dong ◽

Jing Wu ◽

Minxuan Kuang ◽

...

Keyword(s):

Heat Treatment ◽

Lactic Acid ◽

Melt Spinning ◽

Three Dimensional ◽

Composite Fiber ◽

Poly Lactic Acid ◽

Structural Reorganization ◽

Biodegradable Poly ◽

Wet Heat

Biodegradable three-dimensional crimped Poly(Lactide acid)(PLA)/low-melt point poly(Lactide acid) (LM-PLA) side-by-side composite fiber was prepared by regulating the crystallization and disorientation through dry and wet heat treatment.

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Degradation of three dimensional poly(l-lactic acid) scaffolds modified by gelatin

Functional materials ◽

10.15407/fm26.04.845 ◽

2019 ◽

Vol 26 (3) ◽

Keyword(s):

Lactic Acid ◽

Three Dimensional

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Interfacial Tension Measurements in Microfluidic Quasi-Static Extensional Flows

Micromachines ◽

10.3390/mi12030272 ◽

2021 ◽

Vol 12 (3) ◽

pp. 272

Author(s):

Doojin Lee ◽

Amy Q. Shen

Keyword(s):

Interfacial Tension ◽

Microfluidic Device ◽

Extensional Flow ◽

Immiscible Fluids ◽

Droplet Microfluidics ◽

Channel Height ◽

Deformation Model ◽

Droplet Deformation ◽

Extensional Flows ◽

2D Model

Droplet microfluidics provides a versatile tool for measuring interfacial tensions between two immiscible fluids owing to its abilities of fast response, enhanced throughput, portability and easy manipulations of fluid compositions, comparing to conventional techniques. Purely homogeneous extension in the microfluidic device is desirable to measure the interfacial tension because the flow field enables symmetric droplet deformation along the outflow direction. To do so, we designed a microfluidic device consisting of a droplet production region to first generate emulsion droplets at a flow-focusing area. The droplets are then trapped at a stagnation point in the cross junction area, subsequently being stretched along the outflow direction under the extensional flow. These droplets in the device are either confined or unconfined in the channel walls depending on the channel height, which yields different droplet deformations. To calculate the interfacial tension for confined and unconfined droplet cases, quasi-static 2D Darcy approximation model and quasi-static 3D small deformation model are used. For the confined droplet case under the extensional flow, an effective viscosity of the two immiscible fluids, accounting for the viscosity ratio of continuous and dispersed phases, captures the droplet deformation well. However, the 2D model is limited to the case where the droplet is confined in the channel walls and deforms two-dimensionally. For the unconfined droplet case, the 3D model provides more robust estimates than the 2D model. We demonstrate that both 2D and 3D models provide good interfacial tension measurements under quasi-static extensional flows in comparison with the conventional pendant drop method.

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Nonisothermal melt and cold crystallization behaviors of biodegradable poly(lactic acid)/Ti3C2Tx MXene nanocomposites

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-020-10502-7 ◽

2021 ◽

Author(s):

Qian Zhao ◽

Bowen Wang ◽

Chenyuan Qin ◽

Qiuxuan Li ◽

Chuntai Liu ◽

...

Keyword(s):

Lactic Acid ◽

Cold Crystallization ◽

Poly Lactic Acid ◽

Crystallization Behaviors ◽

Biodegradable Poly

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Development of three-dimensional printing filaments based on poly(lactic acid)/hydroxyapatite composites with potential for tissue engineering

Journal of Composite Materials ◽

10.1177/0021998320988568 ◽

2021 ◽

pp. 002199832098856

Author(s):

Marcela Piassi Bernardo ◽

Bruna Cristina Rodrigues da Silva ◽

Luiz Henrique Capparelli Mattoso

Keyword(s):

Tissue Engineering ◽

Lactic Acid ◽

Fused Deposition Modeling ◽

Three Dimensional ◽

Poly Lactic Acid ◽

Scanning Calorimetry ◽

Three Dimensional Printing ◽

Fused Deposition ◽

Deposition Modeling ◽

3D Printed

Injured bone tissues can be healed with scaffolds, which could be manufactured using the fused deposition modeling (FDM) strategy. Poly(lactic acid) (PLA) is one of the most biocompatible polymers suitable for FDM, while hydroxyapatite (HA) could improve the bioactivity of scaffold due to its chemical composition. Therefore, the combination of PLA/HA can create composite filaments adequate for FDM and with high osteoconductive and osteointegration potentials. In this work, we proposed a different approache to improve the potential bioactivity of 3D printed scaffolds for bone tissue engineering by increasing the HA loading (20-30%) in the PLA composite filaments. Two routes were investigated regarding the use of solvents in the filament production. To assess the suitability of the FDM-3D printing process, and the influence of the HA content on the polymer matrix, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were performed. The HA phase content of the composite filaments agreed with the initial composite proportions. The wettability of the 3D printed scaffolds was also increased. It was shown a greener route for obtaining composite filaments that generate scaffolds with properties similar to those obtained by the solvent casting, with high HA content and great potential to be used as a bone graft.

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Poly-(lactic acid) and fibrin bioactive cellularized scaffold for use in bone regenerative medicine: Proof of concept

Journal of Bioactive and Compatible Polymers ◽

10.1177/0883911521996402 ◽

2021 ◽

pp. 088391152199640

Author(s):

Renata Aquino de Carvalho ◽

Valmir Vieira Rocha Júnior ◽

Antonio José Felix Carvalho ◽

Heloisa Sobreiro Selistre de Araújo ◽

Mônica Rosas Costa Iemma ◽

...

Keyword(s):

Lactic Acid ◽

Regenerative Medicine ◽

Platelet Rich Plasma ◽

Three Dimensional ◽

Culture Conditions ◽

Infrapatellar Fat Pad ◽

Dimensional Structure ◽

Poly Lactic Acid ◽

Proof Of Concept ◽

Critical Bone Defects

Bone regenerative medicine (BRM) aims to overcome the limitations of conventional treatments for critical bone defects by developing therapeutic strategies, based on temporary bioactive substitutes, capable of stimulating, sustaining, and guiding tissue regeneration. The aim of this study was to validate the “proof of concept” of a cellularized bioactive scaffold and establish its potential for use in BRM. For this purpose, three-dimensional scaffolds of poly-(lactic acid) (PLA), produced by the additive manufacturing technique, were incorporated into a human platelet-rich plasma (PRP-h) fibrin matrix containing human infrapatellar fat pad mesenchymal stem cells (hIFPMSC). The scaffolds (PLA/finbrin-bioactive) were kept under ideal culture conditions in a medium free from fetal bovine serum and analyzed at 5 and 10 days by Scanning Electron Microscopy (SEM), Fourrier Transform Infrared (FTIR), Circular Dichroism and fluorescence microscopy. The results demonstrated the feasibility of obtaining a rigid, cytocompatible, and cellularized three-dimensional structure. In addition, PRP platelets and leukocytes were able to provide a bioactive environment capable of maintaining the viability of hIFPMSC into scaffolds. The results validate the concept of a customizable, bioactive, cellularized, and non-immunogenic strategy for application in BRM.

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