Abstract: The invention relates to microcapsules with a mixed wall of crosslinked atelocollagen and polyholosides, for example glycosaminoglycans, and to processes for the manufacture of the said microcapsules.According to the invention, the microcapsules comprise a mixed wall of crosslinked atelocollagen and polyholosides, for example glycosaminoglycans, the proportion of polyholosides, for example glycosaminoglycans, relative to the atelocollagen preferably being between 18 and 50% by weight. These microcapsules can be manufactured either by a process involving interfacial crosslinking or by the extrusion of a laminar flow which is broken up by vibrations into individual droplets, which fall into a crosslinking bath.These microcapsules are biocompatible by virtue of the presence of atelocollagen, which has most of the advantageous properties of collagen, namely a very low antigenicity and a perfect biodegradability.

Abstract: A new composition is disclosed which serves as a substitute for the bony matrix material present in bones. The new composition includes an association of collagen-hydroxy-apatite and a glycosaminoglycan. The concentration of the hydroxyapatite is preferably 15 to 25% and the concentration of the glycosaminoglycan is between 1 and 2% per liter of 1% collagen gel. The biomaterial product is useful in applications in reconstructive orthopedic surgery as a substitute for natural bone matrix material.

Abstract: This invention relates to a process and apparatus for freeze-drying, said apparatus comprising freeze-drying shelves disposed inside a freeze-drying enclosure, on which may be placed products or solutions to be freeze-dried, which may be contained in open recipients, as well as cooling and/or heating means associated with and preferably incorporated in said shelves, wherein means forming a thermal shield are disposed between said freeze-drying shelves, thus making it possible to slow down the heat exchanges between the surface of the product to be freeze-dried and the heating and/or cooling elements associated with the shelves. More homogeneous freeze-dried products are obtained in this way.