Abstract: The present invention relates to new plasma or new platelet-rich plasma preparations, new cell dissociation methods, new cell associations or compositions, a method of preparation thereof, a use thereof, devices for the preparation thereof and preparations containing such a platelet-rich plasma preparation and cell associations or compositions. Specifically, the invention provides compositions comprising plasma or platelet-rich plasma alone or in combination with cell preparations for use in tissue regeneration and bone regeneration and pain reduction.