By Yahoo! Southeast Asia Editors – October 21st, 2010

By Anna Valmero,
For Yahoo! Southeast Asia

ILIGAN CITY, LANAO DEL NORTE – Waste materials like fish bones and eggshells can be turned into useful “bioceramics” for coating bone implants in humans, according to a study by Dr. Reynaldo Magdadaro Vequizo of Mindanao State University.

Dr. Reynaldo Magdadaro Vequizo (Photo by

Vequizo headed a project at MSU-Iligan Institute of Technology on the synthesis of a bioceramic materials into a thermal spray coating for bone implants, among other medical and commercial purposes.

“In  Mindanao, we found that there are a lot of agricultural and household waste like the bones of bangus (milkfish), tilapia and other fishes and the egg shells that are usually discarded as garbage and knowing their composition, we studied them as potential bioceramics,” said Vequizo, who is a professor at MSU.

During the recent ASEAN-India Review and Scientific Forum on Thermal Spray held in Tagaytay City, Vequizo presented studies that found the bangus, tilapia and egg shells as viable building blocks for bioceramics due to its calcium composition that is closely related to human bones.

In 2008, local universities like MSU were recommended provide outlines of possible studies on thermal spray.

“Our choice was between studying expensive processes and bioceramic materials. We chose the latter because the materials to make bioceramics made of fish bones and egg shells are there, we have a steady supply of that from Mindanao fish ports,” Vequizo recalls.

“We just pay the restaurants for collection of fish bones and we have a team that collects egg shells from homes and other sources as well.”

Thermal spraying is a coating process in which melted or heated materials are sprayed onto a surface to repair damage surfaces, to improve performance of movable mechanical parts or to prolong the lifespan of an equipment.

Specifically, the fish bones and egg shells are turned into hydroxyapatite compounds, which are inorganic materials that are suited for clinical applications. The material also exhibits “biocompatibility”, meaning it forms direct chemical bond with hard tissues and bones when used as bone filters or ceramic coating in surgical implants.

According to one of their studies, hydroxyapatite compounds made from tilapia bones has promising applications as chemical gas sensor and can be used in the field of chromatography, catalysts, drug delivery systems and fuel cells.

At present, there are already various techniques that are used to synthesize hydroxyapatite compounds from bioceramic materials but these are expensive. Thus, the resulting biocceramics produced are also expensive.

Citing data from the Bureau of Fisheries and Aquatic Resources, Vequizo added that inland tilapia fisheries in the country has produced 723,000 tons of tilapia in 2006, which can provide a good source of tilapia fish bones to make hydroxyapatite compounds.

Another study points to eggshells as source of hydroxyapatite bioceramics through heat treatment and “chemical route” method.

“This provides an alternative way to production of bioceramics that is cheaper than those produced using the wet chemical process that uses expensive materials,” says Vequizo.

Vequizo was sent for a month-long training in India’s Central Glass and Ceramics Research Institute.

“We are also planning to conduct similar studies to bones of tuna and blue marlin, which are also abundant products in Mindanao,” he says.

“There is a lot of promise in the area, especially that we are rich in possible sources of bioceramics in Philippines and we just disregard them as waste. I am optimistic we can make more relevant studies on this area.”

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