Calcium Orthophosphate-Based Bioceramics (Materials 2013 (6) by Sergey V. Dorozhkin,pp.3840-3942; doi:10.3390/ma6093840,ISSN 1996-1944)

Abstract: (pg 3840)

"Calcium orthophosphate scaffolds are designed to induce bone formation and vascularization. These scaffolds are often porous and harbor different biomolecules and/or cells. Therefore, current biomedical applications of calcium orthophosphate bioceramics include bone augmentations, artificial bone grafts, maxillofacial reconstruction, spinal fusion, periodontal disease repairs and bone fillers after tumor surgery. Perspective future applications comprise drug delivery and tissue engineering purposes because calcium orthophosphates appear to be promising carriers of growth factors, bioactive peptides and various types of cells."

Introduction: (pg 3841)

"One should note that, in 2010, only in the USA the sales of bone graft substitutes were valued at ~$1.3 billion with a forecast of ~$2.3 billion by 2017 [5]"

[Ref No 5. US Bone Grafts Market to Reach US$2.3 Billion by 2017, According to New Report by Global Industry Analysts, Inc. Available online: http://www.prweb.com/releases/bone_grafts/standard_ bone_allografts/prweb8953883.htm (accessed on 3 September, 2013).]

Biological Properties and in Vivo Behavior: (pg 3871)

"It is important to stress, that a distinction between the bioactive and bioresorbable bioceramics might be associated with structural factors only. Namely, bioceramics made from non-porous, dense and highly crystalline HA behaves as a bioinert (but a bioactive) material and is retained in an organism for at least 5–7 years without noticeable changes (Figure 2 bottom), while a highly porous bioceramics of the same composition can be resorbed approximately within a year. Furthermore, submicron-sized HA powders are biodegraded even faster than the highly porous HA scaffolds."

[Ref141. Okuda, T.; Ioku, K.; Yonezawa, I.; Minagi, H.; Gonda, Y.; Kawachi, G.; Kamitakahara, M.; Shibata, Y.; Murayama, H.; Kurosawa, H.; et al. The slow resorption with replacement by bone of a hydrothermally synthesized pure calcium-deficient hydroxyapatite. Biomaterials 2008, 29, 2719–2728.]

Conclusions and Outlook: (pg 3888)

"In spite of the great progress, there is still a great potential for major advances to be made in the field of calcium orthophosphate bioceramics [910]. This includes requirements for:
1. Improvement of the mechanical performance of existing types of bioceramics.
2. Enhanced bioactivity in terms of gene activation.
3. Improvement in the performance of biomedical coatings in terms of their mechanical stability and ability to deliver biological agents.
4. Development of smart biomaterials capable of combining sensing with bioactivity.
5. Development of improved biomimetic composites."

[Ref No 910. Vallet-Regí, M. Evolution of bioceramics within the field of biomaterials. Comptes Rendus Chimie 2010, 13, 174–185]

"Furthermore, in future, it should be feasible to design a new generation of gene-activating calcium orthophosphate based scaffolds tailored for specific patients and disease states. Perhaps, sometime bioactive stimuli will be used to activate genes in a preventative treatment to maintain the health of aging tissues. Currently this concept seems impossible. However, we need to remember that only ~40 years ago the concept of a material that would not be rejected by living tissues also seemed impossible [654]."

 [Ref No 654.Hench, L.L. Challenges for bioceramics in the 21st century. Am. Ceram. Soc. Bull. 2005, 84, 18–21.]