Regenerative medicine is a scientific field that improves and repairs diseased and injured tissues. Three-dimensional (3D) printing is an innovative technology that provides a new application field for regenerative medicine. 3D printed scaffolds by programming pore sizes and shapes serve as a temporary basis for cells until the natural extracellular matrix (ECM) is reconstructed. Dermal fibroblasts are mesenchymal cells located in the dermal skin layer that produce and organize ECM components. They play an essential role in skin wound healing and fibrosis. The aim of this study is to analyze the viability, adhesion, distribution, and collagen IV expression of human dermal fibroblasts (HDFs) seeded on 3D printed polylactic acid (PLA), polyethylene terephthalate (PET), and poly-ε-caprolactone (PCL) scaffolds in vitro. HDFs were seeded on scaffolds or tissue culture plastic plates as control and were cultured for 1 and 3 days. 3D PLA, PCL, and PET scaffolds were prepared using a custom made fused deposition modeling printer. The cell viability was measured by WST-1 assay on days 1 and 3. The cell adhesion was evaluated by scanning electron microscopy (SEM).The distribution was analyzed by hematoxylin and eosin (H&E) staining. Collagen IV expression was analyzed by immunohistochemical (IHC) staining.On day 1, the viability of HDFs on the 3D PLA scaffolds was significantly higher than PCL scaffolds. On day 3, the viability of HDFs on 3D PLA and PET scaffolds was significantly higher than PCL scaffolds. SEM images showed that HDFs on 3D PLA scaffolds attached the surfaces, filled the interfiber gaps and maintained their tissue specific morphology on day 3 compared to PCL and PET scaffolds. Histological images stained with H&E demonstrated that the distribution of HDFs on 3D PLA scaffolds was uniform on days 1 and 3. Collagen IV staining was more intense in HDFs on 3D PLA scaffolds on days 1 and 3. This study shows that 3D PLA scaffolds create a appropriate environment for cell viability, adhesion, distribution and may provide a high advantage in skin tissue regeneration.

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Tissue engineering is an interdisciplinary field for the design of functional constructs that aid to repair damaged or diseased tissue. Threedimensional (3D) printing is a growing technology that offers new opportunities for tissue engineering. Thermoplastic polyurethane (TPU) is a member of the polyurethane class. TPUs are commonly used in medical applications with their biocompatible, superior mechanical properties and shape memory behavior. Macrophages are key regulators of tissue homeostasis, inflammation, and regeneration. They play crucial roles in initial immune response to implants. In this study, we aimed to investigate the viability, adhesion, and distribution properties of human THP-1 macrophages seeded on 3D printed TPU scaffolds in vitro. The expression of CD68 and CD10 was also analyzed in human THP-1 macrophages on 3D TPU scaffolds. THP-1 macrophages treated with phorbol-12-myristate-13-acetate (PMA) were seeded on 3D TPU scaffolds or tissue culture plastic plates as control and cultured for 1, 3, 7, and 14 days. 3D TPU scaffolds were prepared using a custom made fused deposition modeling printer. The cell viability was measured by WST-1 assay on days 1 and 3. The cell adhesion was evaluated by scanning electron microscopy (SEM). The cell distribution was analyzed by hematoxylin and eosin (H&E) staining. Expression of CD10 and CD68 was analyzed by immunohistochemical (IHC) staining. The viability of THP-1 macrophages on 3D TPU scaffolds was lower than their control groups on days 1 and 3. SEM images showed THP-1 macrophage attachment on the 3D TPU scaffold surface with round and elongated morphologies. H&E staining demonstrated that THP-1 macrophages showed eosinophilic cytoplasm and large nuclei. CD68 staining was more intense in THP-1 macrophages on 3D TPU scaffolds on day 3 compared to days 1, 7 and 14. CD10 staining was more intense on day 1 compared to days 3, 7, and 14. Our results show that 3D TPU scaffolds are biocompatible with macrophages and might be a potential biomaterial for medical applications.

Humans require treatment due to the loss of tissues after trauma and diseases. Tissue engineering is a growing field of engineering and medical science to restore, maintain, or improve function of damaged or diseased tissues. The use of three-dimension (3D) scaffolds in particular offers a potential option for patients with tissue deficiency. Polylactic acid (PLA), poly-caprolactone (PCL), polyether-ether-ketone (PEEK), and thermoplastic polyurethane (TPU) are biomaterials that are commonly used in tissue engineering. Their applications of pure material or composite and supportive materials are of great importance for clinical practices. This review provides information on biomaterials and major areas of application and discusses their advantages and disadvantages against each other. The literature search from the database PubMed was done for the key words 3D PLA, PCL, PEEK, and TPU separately and 2029 articles were identified. These articles were limited according to clinical, in vivo and observational studies published in English and 140 articles were evaluated for this review. We selected the main articles according to the current data of 3D scaffolds and identical articles were removed. Fifty articles were included in the review. Many studies have reported the advantages of 3D scaffolds with composite or supplement materials over pure materials in the medical treatment. The advances in the development of new 3D scaffolds hold great promise for the prospective applications in the medical treatment.

Objective: Fibroblasts are mesenchymal cells of dermal origin that provide structural integrity for connective tissue by producing the extracellular matrix proteins. They are the dominant component of the tumor microenvironment and are then referred to as cancer-associated fibroblasts (CAFs). CAFs play an important role in cancer cell growth. Autophagy is an intracellular self-degradative process that balances cell energy sources and regulates tissue homeostasis. Autophagy is now considered a critical process in skin health and skin cancer. The objective of this study is to investigate the effect of lipopolysaccharide (LPS) on the autophagy mechanism in human dermal fibroblasts (HDFs) in vitro. Methods: HDFs were incubated with 0.1, 0.5, 1 and 5 μg/mL of LPS for 24 h. The viability of cells was determined using WST-1 assay. The protein expressions of beclin-1, p62, LC3-I and LC3-II were analyzed by Western blotting. Results: The viability of HDFs incubated with 0.1, 0.5, 1 and 5 μg/mL of LPS did not show any significant differences compared to untreated cells. Beclin-1 protein expression was upregulated with all LPS concentrations. The protein expression of p62 was also induced with all LPS concentrations. Furthermore, the ratio of LC3-II/LC3-I protein expression was increased with all LPS concentrations. Conclusion: Our results demonstrate that LPS inhibits autophagy in HDFs through the upregulation of p62 and LC3 protein expression. These findings suggest the relationship between inflammation and autophagy in skin cells and might contribute to understanding the key role of autophagy in the development of skin cancer.