Targeting and Dissolution Characteristics of Bone Forming and Antibacterial Drugs by Harnessing the Structure of Microspherical Shells from Coral Beach Sand


  • This work was funded by ARC Discovery; grant number: DP0558913 and COMET, Commonwealth of Australia Grants. SEM imaging was undertaken by Dr R. Wuhrer, NMR studies by Dr R. Shimmonn (both researchers are from the University of Technology Sydney). Our thanks also go to Prof A. Johnson from the University of Sydney for the micro-CT analysis work.


Pharmaceutical drugs for the treatment of metabolic bone diseases lead to a number of side effects due to the their uncontrollable dispersion throughout the body.1 Therefore, many groups directed their research to develop devices that are targeted to specific organs or tissues and release the encapsulated drug in a highly regulated way.2–7 The development of completely resorbable bone-filling biomaterials delivering drugs would offer a therapeutic approach of drug release and bone augmentation in a simple one-step process.8–11 The biomaterials selected needs custom designs, to control the quantity and the duration of drug release and at the same time inducing desirable host cell responses and preventing bacterial infection.12–15 Current synthetic biomaterials produced as drug delivery microspheres due to production difficulties contain not very well designed interconnected pores and fail to fill these pertinent requirements.

Turning directly to nature such as marine structures for inventive solutions can help to solve these problems due to their structure, chemistry and architecture and their unique designs.16–20

We demonstrate -for the first time- the potential of unique coral shells with specific microspherical structure and highly organised interconnected intra-pore designs to offer a number of desired functions for targeted delivery of Bisphosphonate (BP) (paminodrate) and an antibiotic (Gentamicin) for bone regeneration, repair and preventive antibacterial slow drug delivery.