The use of additive manufacturing (AM) technologies is a relatively young research area in modern medicine. This technology offers a fast and effective way of producing implants, tissues, or entire organs individually adapted to the needs of a patient. Today, a large number of different 3D printing technologies with individual application areas are available. This review is intended to provide a general overview of these various printing technologies and their function for medical use. For this purpose, the design and functionality of the different applications are presented and their individual strengths and weaknesses are explained. Where possible, previous studies using the respective technologies in the field of tissue engineering are briefly summarized.

Skin regeneration is a quite complex process. Epidermal differentiation alone takes about 30 days and is highly regulated. Wounds, especially chronic wounds, affect 2% to 3% of the elderly population and comprise a heterogeneous group of diseases. The prevailing reasons to develop skin wounds include venous and/or arterial circulatory disorders, diabetes, or constant pressure to the skin (decubitus). The hallmarks of modern wound treatment include debridement of dead tissue, disinfection, wound dressings that keep the wound moist but still allow air exchange, and compression bandages. Despite all these efforts there is still a huge treatment resistance and wounds will not heal. This calls for new and more efficient treatment options in combination with novel biocompatible skin scaffolds. Cold atmospheric pressure plasma (CAP) is such an innovative addition to the treatment armamentarium. In one CAP application, antimicrobial effects, wound acidification, enhanced microcirculations and cell stimulation can be achieved. It is evident that CAP treatment, in combination with novel bioengineered, biocompatible and biodegradable electrospun scaffolds, has the potential of fostering wound healing by promoting remodeling and epithelialization along such temporarily applied skin replacement scaffolds.

(1) Background: The aim of the present study was the biocompatibility analysis of a novel xenogeneic vascular graft material (PAP) based on native collagen won from porcine aorta using the subcutaneous implantation model up to 120 days post implantationem. As a control, an already commercially available collagen-based vessel graft (XenoSure®) based on bovine pericardium was used. Another focus was to analyze the (ultra-) structure and the purification effort. (2) Methods: Established methodologies such as the histological material analysis and the conduct of the subcutaneous implantation model in Wistar rats were applied. Moreover, established methods combining histological, immunohistochemical, and histomorphometrical procedures were applied to analyze the tissue reactions to the vessel graft materials, including the induction of pro- and anti-inflammatory macrophages to test the immune response. (3) Results: The results showed that the PAP implants induced a special cellular infiltration and host tissue integration based on its three different parts based on the different layers of the donor tissue. Thereby, these material parts induced a vascularization pattern that branches to all parts of the graft and altogether a balanced immune tissue reaction in contrast to the control material. (4) Conclusions: PAP implants seemed to be advantageous in many aspects: (i) cellular infiltration and host tissue integration, (ii) vascularization pattern that branches to all parts of the graft, and (iii) balanced immune tissue reaction that can result in less scar tissue and enhanced integrative healing patterns. Moreover, the unique trans-implant vascularization can provide unprecedented anti-infection properties that can avoid material-related bacterial infections.

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Background/Aim: The aim of this study was the conception, production, material analysis and cytocompatibility analysis of a new collagen foam for medical applications. Materials and Methods: After the innovative production of various collagen sponges from bovine sources, the foams were analyzed ex vivo in terms of their structure (including pore size) and in vitro in terms of cytocompatibility according to EN ISO 10993-5/-12. In vitro, the collagen foams were compared with the established biomaterials cerabone and Jason membrane. Materials cerabone and Jason membrane. Results: Collagen foams with different compositions were successfully produced from bovine sources. Ex vivo, the foams showed a stable and long-lasting primary structure quality with a bubble area of 1,000 to 2,000 μm 2 . In vitro, all foams showed sufficient cytocompatibility. Conclusion: Collagen sponges represent a promising material for hard and soft tissue regeneration. Future studies could focus on integrating and investigating different additives in the foams.Collagen is the most abundant protein in the human body and constitutes around 25-30% of the total amount of protein (1, 2). Up to now, 28 different types of collagen have been discovered (3). As an essential part of the extracellular matrix (ECM), different collagen types can be found in bones, cartilage, tendons and skin, as well as in teeth, cornea and blood vessels (4-6). Collagen is biocompatible and completely biodegradable by endogenous human proteases (7, 8). In addition, it is characterized by its ability to positively influence cell adhesion, cell proliferation, and differentiation (1,4,9). These qualities can be further increased by adding growth and differentiation factors to the collagen matrix (10,11). Antibacterial properties can be developed by adding nanoparticles such as AgNP (12,13). By additional physical as well as chemical cross-linking (6)(7)(8)14) or the combination of different types of collagen with and without additional bioabsorbable materials, the usually short-lasting degradation time of natural collagen can be further extended, which ensures a sufficient durability (e.g., in wound dressings) (15,16).These properties make collagen as one of the most promising biomaterials in modern medicine. Depending on the area of application, it is obtained autogenously, allogenically or xenogenically (17,18). Collagen is widely used as a wound dressing in the treatment of acute or chronic wounds (19), burn wounds (20, 21) or sites of skin donation and skin grafts ( 22), through its ability of shielding the wound from infection and contamination, reducing scarring, absorbing wound exudate, and promoting the skin's natural regeneration ability (19,23,24). In addition, collagen is able to bind platelets and thus activate the coagulation cascade (25, 26), which makes it very suitable for acute use in wound care. Resorbable barrier membranes made of collagen are of great importance in guided bone regeneration (GBR) for dentistry and oral and maxillofacial surgery, in order to...