The present invention discloses novel crosslinked biomaterial compsotions which are prepared using hydrophobic polymers as a crosslinking agent. Preferred hydrophobic polymers are those that contain two or more reactive succinimidyl groups, including disuccinimidyl suberate, bix(sulfosuccinimidyl) suberate, and dithiobis(succinimidylpropionate). Crosslinked biomaterial compositions prepared using mixtures of hydrophobic and hydrophilic crosslinking agents are also disclosed. The compositions of the present invention can be used to prepare formed implants for use in a variety of medical applications.