Controlled drug delivery from composites of nanostructured porous silicon and poly(L-lactide)

Steven McInnes, Yazad Irani, Keryn Williams, Nicolas Voelcker

    Research output: Contribution to journalArticlepeer-review

    54 Citations (Scopus)


    Aims: Porous silicon (pSi) and poly(L-lactide) (PLLA) both display good biocompatibility and tunable degradation behavior, suggesting that composites of both materials are suitable candidates as biomaterials for localized drug delivery into the human body. The combination of a pliable and soft polymeric material with a hard inorganic porous material of high drug loading capacity may engender improved control over degradation and drug release profiles and be beneficial for the preparation of advanced drug delivery devices and biodegradable implants or scaffolds. Materials & methods: In this work, three different pSi and PLLA composite formats were prepared. The first format involved grafting PLLA from pSi films via surface-initiated ring-opening polymerization (pSi-PLLA [grafted]). The second format involved spin coating a PLLA solution onto oxidized pSi films (pSi-PLLA [spin-coated]) and the third format consisted of a melt-cast PLLA monolith containing dispersed pSi microparticles (pSi-PLLA [monoliths]). The surface characterization of these composites was performed via infrared spectroscopy, scanning electron microscopy, atomic force microscopy and water contact angle measurements. The composite materials were loaded with a model cytotoxic drug, camptothecin (CPT). Drug release from the composites was monitored via fluorimetry and the release profiles of CPT showed distinct characteristics for each of the composites studied. Results: In some cases, controlled CPT release was observed for more than 5 days. The PLLA spin coat on pSi and the PLLA monolith containing pSi microparticles both released a CPT payload in accordance with the Higuchi and Ritger-Peppas release models. Composite materials were also brought into contact with human lens epithelial cells to determine the extent of cytotoxicity. Conclusion: We observed that all the CPT containing materials were highly efficient at releasing bioactive CPT, based on the cytotoxicity data. Original submitted 16 December 2010; Revised submitted 29 September 2011; Published online 6 March 201.

    Original languageEnglish
    Pages (from-to)995-1016
    Number of pages22
    Issue number7
    Publication statusPublished - Jul 2012


    • composite material
    • glaucoma
    • localized drug delivery
    • poly(L-lactide)
    • porous silicon
    • uveitis


    Dive into the research topics of 'Controlled drug delivery from composites of nanostructured porous silicon and poly(L-lactide)'. Together they form a unique fingerprint.

    Cite this