The present invention relates to compositions comprising biologically active chitinous oligomers and their endotoxin purified and partially deacetylated chitin polymer precursors, and their use in pharmaceutical compositions, biomaterial compositions, medical devices, and processes to produce the said oligomers. More specifically the present invention relates to novel compositions and processes to produce such compositions. The compositions include therapeutic hetero polymer and hetero oligomer compositions comprising specific sequences of N-acetyl glucosamine and glucosamine, developed to optimize chemical and structural features which are important for the therapeutic activity of these compositions. In addition, the present invention provides methods to use degree of deacetylation of a partially deacetylated chitin polymer in order to modulate physical and biological parameters in a calcium phosphate composite for bone implant applications.