| AVS 61st International Symposium & Exhibition | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI+AS-TuA |
| Session: | Characterization of Biointerfaces |
| Presenter: | David Scurr, University of Nottingham, UK |
| Correspondent: | Click to Email |
The developments in pharmaceutical delivery systems such as injectable drug eluting microparticles [1], topically applied medicines [2] and wound dressings [3] can be utilised in areas such as the treatment of HIV, basal cell carcinoma and microbial infections respectively. In this study, the characterisation of such systems has been performed using time of flight secondary ion mass spectrometry (ToF-SIMS), x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM).
Injectable controlled release formulations were produced by spray drying two biocompatible polymers, poly(lactic-co-glycolic acid) (PLGA) and polyvinylpyrrolidone (PVP). The samples were analysed using a range of techniques including ToF-SIMS, XPS and AFM showing that the samples were hollow microparticles with a surface PLGA rich phase and an underlying PVP phase [1]. Additionally, more complex ternary systems incorporating PLGA, PVP and a poorly soluble investigational drug compound were also analysed. These studies highlighted the influence of sample processing parameters and drug concentration upon factors such as surface composition which is influential in the drug release properties of the systems.
The permeation of an antibacterial drug, chlorhexidine, into skin tissue has been illustrated using ToF-SIMS chemical imaging of cross-sectioned treated skin samples [2]. This methodology has been further applied to investigate the topical delivery of imiquimod, a drug used in the treatment of basal cell carcinoma. This work demonstrates the ability of the ToF-SIMS technique to correlate chemical species specific to the drug with physiological features within tissue cross-sections. Further application of ToF-SIMS chemical mapping has also been used to successfully differentiate chemically dissimilar regions of anti-microbial films which could be developed as wound dressing materials. Observations made for these materials using a combination of ToF-SIMS and AFM analysis revealed the distribution of the active agents upon the surface which would be relevant to the the anti-microbial performance.
[1] Meeus, Scurr, Amssoms, Davies, Roberts, and Van den Mooter (2014) Molecular Pharmaceutics, 10 (8)
[2] Judd, Scurr, Heylings, Wan, and Moss (2013) Pharmaceutical Research, 30 (7)
[3] Liakos, Rizzello, Scurr, Pompa, Bayer and Athanassiou (2014) International Journal of Pharmacy, 463 (2)