The effect of injection using narrow-bore needles on mammalian cells: administration and formulation considerations for cell therapies (original) (raw)

Translation of cell therapies to the clinic: characteristics of cell suspensions in large diameter injection cannula

Cell transplantation, 2014

With the use of cell replacement therapies as a realistic prospect for conditions such as Parkinson's and Huntington's diseases, the logistics of the delivery of cell suspensions to deep brain targets is a topic for consideration. Because of the large cannulae required for such procedures, we need to consider the behaviour of cell suspensions within the cannulae if we are to ensure that the injected cells are distributed as intended within the target tissue. We have investigated the behaviour of primary embryonic cell suspensions of neural tissue, in cannulae of different diameters, using a protocol designed to mimic the handling and injection of cells during clinical application. Internal cannula diameter had a large effect on the distribution of cells during their dispensation from the syringe. In vertical, or near vertical cannulae, cells settled towards the tip of the needle, and were dispensed unevenly, with the majority of cells emerging in the first 10-20% of the inje...

Injectable gels for tissue engineering

The Anatomical Record, 2001

Recently, tissue engineering approaches using injectable, in situ gel forming systems have been reported. In this review, the gelation processes and several injectable systems that exhibit in situ gel formation at physiological conditions are discussed. Applications of selected injectable systems (alginate, chitosan, hyaluronan, polyethylene oxide/polypropylene oxide) in tissue engineering are also described. Injectable polymer formulation can gel in vivo in response to temperature change (thermal gelation), pH change, ionic cross-linking, or solvent exchange. Kinetics of gelation is directly affected by its mechanism. Injectable formulations offer specific advantages over preformed scaffolds such as: possibility of a minimally invasive implantation, an ability to fill a desired shape, and easy incorporation of various therapeutic agents. Several factors need to be considered before an injectable gel can be selected as a candidate for tissue engineering applications. Apart from tissue-specific cell–matrix interactions, the following gel properties need to be considered: gelation kinetics, matrix resorption rate, possible toxicity of degradation products and their elimination routes, and finally possible interference of the gel matrix with histogenesis. Anat Rec 263:342–349, 2001. © 2001 Wiley-Liss, Inc.