Related Experiment Video
Updated: Feb 10, 2026

Porous Silicon Microparticles for Delivery of siRNA Therapeutics
Published on: January 15, 2015
Improved delivery of PLGA microparticles and microparticle-cell scaffolds in clinical needle gauges using modified
Omar Qutachi1, Emma J Wright2, Gemma Bray1
1Division of Regenerative Medicine and Cellular Therapies, Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, NG7 2RD, UK.
Abstract:
Polymer microparticles are widely used as acellular drug delivery platforms in regenerative medicine, and have emerging potential as cellular scaffolds for therapeutic cell delivery. In the clinic, PLGA microparticles are typically administered intramuscularly or subcutaneously, with the clinician and clinical application site determining the precise needle gauge used for delivery. Here, we explored the role of needle diameter in microparticle delivery yield, and develop a modified viscosity formulation to improve microparticle delivery across a range of clinically relevant needle diameters. We have identified an optimal biocompatible formulation containing 0.25% pluronic F127 and 0.25% carboxymethyl cellulose, which can increase delivery payload to 520% across needle gauges 21-30G, and note that needle diameter impacts delivery efficacy. We use this formulation to increase the delivery yield of PLGA microparticles, and separately, PLGA-cell scaffolds supporting viable mesenchymal stem cells (MSCs), demonstrating the first in vitro delivery of this cell scaffold system. Together, these results highlight an optimal formulation for the delivery of microparticle and microparticle-cell scaffolds, and illustrate how careful choice of delivery formulation and needle size can dramatically impact delivery payload.
Related Concept Videos
Insulin Formulations: Types and Delivery
Short-acting insulins are divided into...
Viscosity
The SI unit of viscosity is...
Surface Tension, Capillary Action, and Viscosity
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
Viscosity of Fluid
Pressure Gauges
Design Example: Strain Gauge Bridge or Wheatstone Bridge

