The application of various materials in biomedical procedures has recently experienced rapid growth. One area that is currently receiving significant attention from the scientific community is the treatment of a number of different types of bone-related diseases and disorders by using biodegradable polymer-ceramic composites. Biomaterials, the most common materials used to repair or replace damaged parts of the human body, can be categorized into three major groups: metals, ceramics, and polymers. Composites can be manufactured by combining two or more materials to achieve enhanced biocompatibility and biomechanical properties for specific applications. Biomaterials must display suitable properties for their applications, about strength, durability, and biological influence. Metals and their alloys such as titanium, stainless steel, and cobalt-based alloys have been widely investigated for implant-device applications because of their excellent mechanical properties. However, these materials may also manifest biological issues such as toxicity, poor tissue adhesion and stress shielding effect due to their high elastic modulus. To mitigate these issues, hydroxyapatite (HA) coatings have been used on metals because their chemical composition is similar to that of bone and teeth. Recently, a wide range of synthetic polymers such as poly (l-lactic acid) and poly (l-lactide-co-glycolide) have been studied for different biomedical applications, owing to their promising biocompatibility and biodegradability. This article gives an overview of synthetic polymer-ceramic composites with a particular emphasis on calcium phosphate group and their potential applications in tissue engineering. It is hoped that synthetic polymer-ceramic composites such as PLLA/HA and PCL/HA will provide advantages such as eliminating the stress shielding effect and the consequent need for revision surgery.

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Self-assembled mixed-brushes with co-continuous surface morphologies were developed from melt of poly(ethylene glycol)-b-polystyrene (PEG-b-PS) and poly(ethylene glycol)-bpoly(methyl methacrylate) (PEG-b-PMMA) diblock copolymers by a self-seeding technique.Some features of solution-grown matrix-dispersed mixed-brushes having controllable characteristics were briefly recalled and compared with the behavior of corresponding meltgrown mixed-brushes. The preceding observations implied some major differences between two growth systems. An obvious deduction made from atomic force microscopy height images was that the patterned leopard-skin like surface morphology of solution induced mixed-brush single crystals changed to co-continuous morphologies in melt state. Beside the alteration of growth environment from solution to the melt, this phenomenon was assigned to the dominant kinetic effect replaced instead of the prevailed thermodynamic effect in dilute solution systems. The ratio of PMMA-to PS-covered surface area on the substrate, increased from 20/80 for the solution-grown mixed-brush single crystals to 50/50 for the melt-grown ones. Owing to 2 accelerated kinetic in melt-grown mixed-brush single crystals, for a same molecular weight, the thickness of a melt-grown mixed-brush single crystal was significantly greater than that observed for solution-grown mixed-brush single crystal. Similar trends, nevertheless, were observed for the thickness changes with molecular weight and crystallization temperature. The lateral sizes of melt-grown single crystals were about 4-fold larger than those for solution-grown single crystals (e.g., 24 vs. 6 µm). The thicknesses were also proved by the interface distribution function of small angle x-ray scattering analysis.

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