Cell preparations for extemporaneous use, useful for healing and rejuvenation in vivo

#The present invention is related to the field of tissue regeneration, especially skin, cartilage, muscle, tendon, adipose tissue, cornea, peripheral nerves, spine and bone regeneration. It concerns more particularly new cell preparations as a biological scaffold, a method of preparation thereof, a use thereof, a device for the preparation thereof and preparations containing such cell preparation for extemporaneous use.

#The importance of biological autologous materials in the healing process has been well documented. Most importantly, two biological autologous materials have been shown to be directly implicated in the formation of the structure of blood clots, which provide a haemostatic barrier whose role is to ensure hemostasis and seal the wound: (1) fibrin, which derives from the separation of plasma fibrinogen into two strands through the action of thrombin, and (2) the activated membranes of platelets.

#The wound healing process is generally presented as the succession of a coagulation phase, an inflammatory process and a regeneration process.

#FIG. 1 is a schematic representation of the variation of concentration in growth factors (PDGF-AB, EGF and VEGF) of a platelet concentrate composition according to the invention versus time (T in hours) after the centrifugation step in the preparation process of the invention.

#FIG. 2 is a schematic representation of the outcome of the treatment of a skin graft donor site with a preparation containing a platelet concentrate composition according to the invention in comparison with a control group in terms of healing time in days (HT), pain at day 5 on a scale 0 to 10 (P) and epithelization at day 5 on a scale 0 to 7 (E). Control group: C, platelet-rich preparation alone: RegenPRP™, platelet-rich preparation and autologous keratinocytes: RegenExtracell™. The dotted line indicates when the first bandage is changed at day 5.

#FIG. 3 represents the morphology of a human fibroblast expanded in cell preparation according to the invention under the condition described in Example 7, showing branching and filopodia×5,000 (Olympus® inverted microscope).

#The following paragraphs provide definitions of the terms according to the invention and are intended to apply uniformly throughout the specification and claims unless an otherwise expressly set out definition provides a broader definition.

#By the expression “thixotropic” is meant a gel that becomes more fluid as a result of agitation or pressure, i.e. a gel which viscosity is decreasing as a result of agitation or pressure. The term viscosity refers to those characteristics of the specified material(s) determining the degree of gelation, such as for example the firmness or hardness of the material, the degree to which the material resists flowing like a fluid. A thixotropic gel according to the invention comprising a polyester gel or a mixture thereof which is water insoluble and chemically inert to blood constituents which can be used in accordance with the invention. Typical thixotropic gels are used in blood cells separation for diagnostics and proteomics purposes.

#By the expression “point-of-care” is meant all services provided to patients at the bedside.