Anna Gustafsson

Replicating the complex physiology of human skin in vitro remains a challenge for cutaneous oncology. Although several three-dimensional (3D) skin and melanoma models have been developed, reproducible skin equivalent systems that enable direct and standardized comparisons between healthy and melanoma-containing skin remain valuable experimental tools. This study aimed to optimize and characterize skin equivalents containing either melanocytes or melanoma cells and to evaluate their utility as platforms for investigating melanoma-associated skin biology and UVB-induced responses in vitro. To achieve this, 3D skin equivalents containing fibroblasts, keratinocytes, and either melanocytes or melanoma cells were reconstructed on a polystyrene scaffold to generate healthy (mc) and melanoma (mm) models. Morphological characteristics were compared with clinically verified human tissue sections, and functional responses to UVB irradiation were assessed with a focus on the kynurenine pathway. The models demonstrated a distinct dermal–epidermal architecture and distinguishable melanoma-associated features, including epidermis-confined melanoma cell clusters, in mm constructs. UVB exposure induced differential responses between models, including significant differences in kynurenine pathway regulation. These findings suggest that the developed skin equivalents provide a reproducible in vitro platform for studying melanoma-associated skin biology and treatment-related metabolic responses and may support future mechanistic studies of skin cancer progression.

Early detection of cancer via biomarkers is vital for improving patient survival rates. In the case of skin cancers, low-molecular-weight biomarkers can penetrate the skin barrier, enabling non-invasive sampling at an early stage. This study focuses on detecting tryptophan (Trp) and kynurenine (Kyn) on the surface of reconstructed 3D melanoma and melanocyte models. This is examined in connection with IDO-1 and IL-6 expression in response to IFN-γ or UVB stimulation, both crucial factors of the melanoma tumor microenvironment (TME). Using a polystyrene scaffold, full-thickness human skin equivalents containing fibroblasts, keratinocytes, and melanocytes or melanoma cells were developed. The samples were stimulated with IFN-γ or UVB, and Trp and Kyn secretion was measured using HPLC-PDA and HPLC-MS. The expression of IDO-1 and IL-6 was measured using RT-qPCR. Increased Trp catabolism to Kyn was observed in IFN-γ-stimulated melanoma and melanocyte models, along with higher IDO-1 expression. UVB exposure led to significant changes in Kyn levels but only in the melanoma model. This study demonstrates the potential of skin surface Trp and Kyn monitoring to capture TME metabolic changes. It also lays the groundwork for future in vivo studies, aiding in understanding and monitoring skin cancer progression.

Spherical, multicellular aggregates of tumor cells, or three-dimensional (3D) tumor models, can be grown from established cell lines or dissociated cells from tissues in a serum-free medium containing appropriate growth factors. Air–liquid interfaces (ALIs) represent a 3D approach that mimics and supports the differentiation of respiratory tract and skin 3D models in vitro. Many 3D tumor cell models are cultured in conjunction with supporting cell types, such as fibroblasts, endothelial cells, or immune cells. To further mimic the in vivo situation, several extracellular matrix models are utilized to support tumor cell growth. Scaffolds used for 3D tumor cell culture growth include both natural and synthetic hydrogels. Three-dimensional cell culture experiments in vitro provide more accurate data on cell-to-cell interactions, tumor characteristics, drug discovery, metabolic profiling, stem cell research, and diseases. Moreover, 3D models are important for obtaining reliable precision data on therapeutic candidates in human clinical trials before predicting drug cytotoxicity. This review focuses on the recent literature on three different tissue types of 3D tumor models, i.e., tumors from a colorectal site, prostate, and skin. We will discuss the establishment of 3D tumor cell cultures in vitro and the requirement for additional growth support.

Background: After completing university education, biomedical laboratory scientists work in clinical laboratories, in biomedical research laboratories, in biotech, and in pharmaceutical companies. Laboratory diagnostics have undergone rapid development over the recent years, with the pace showing no signs of abatement. This rapid development challenges the competence of the staff and will most certainly influence the education of future staff. This study aimed to examine what was considered the necessary competencies needed to pursue a career as a biomedical laboratory scientist. Methods: A modified Delphi technique was used, with the panel of experts expressing their views in a series of three questionnaire. Consensus was defined as the point which 75 % or more of the panel participants agreed that a particular competency was necessary. Results: The study highlights the perceived importance of mostly generic competencies that relate to quality, quality assurance, and accuracy, as well as different aspects of safety, respect, trustworthiness (towards patients/clients and colleagues), and communication skills. The results also stress the significance of self-awareness and professionality. Conclusions: We identified important competencies for biomedical laboratory scientists. Together with complementary information from other sources, i.e., guidelines, laws, and scientific publications, the competencies identified can be used as learning outcomes in a competency-based education to provide students with all the competencies needed to work as professional biomedical laboratory scientists.

Background After completing university education Biomedical Laboratory Scientists work in clinical laboratories, in biomedical research laboratories, in biotech, and in pharmaceutical companies. Laboratory diagnostics have undergone rapid development over the recent years, and the pace shows no signs of abatement. Rapid development challenges the competence of the staff and will most certainly influence the education of future staff. This study was aimed to examine what was considered the necessary competencies needed to pursue a career as a Biomedical Laboratory Scientist Methods A modified Delphi technique was used, and the panel of experts expressed their views in a three questionnaire series. Consensus was defined as the point when 75% or more of the panel participants agreed that a particular competence was necessary. Results The study highlights the perceived importance of mostly generic competencies that relate to quality, quality assurance, and accuracy, as well as different aspects of safety, respect, trustworthiness (towards patients/clients and colleagues), and communication skills. The results also stress the significance of self-awareness and professionality. Conclusions We identified important competencies for Biomedical Laboratory Scientists. Together with complementary information from other sources, i.e., guidelines, laws, and scientific publications, the competencies identified can be used as learning outcomes in a competency-based education to provide students with all competencies needed to work as professional Biomedical Laboratory Scientists.

The generation of reactive oxygen species presents a destructive challenge for the skin organ and there is a clear need to advance skin care formulations aiming at alleviating oxidative stress. The aim of this work was to characterize the activity of the antioxidative enzyme catalase in keratinocytes and in the skin barrier (i.e., the stratum corneum). Further, the goal was to compare the activity levels with the corresponding catalase activity found in defatted algae biomass, which may serve as a source of antioxidative enzymes, as well as other beneficial algae-derived molecules, to be employed in skin care products. For this, an oxygen electrode-based method was employed to determine the catalase activity and the apparent kinetic parameters for purified catalase, as well as catalase naturally present in HaCaT keratinocytes, excised stratum corneum samples collected from pig ears with various amounts of melanin, and defatted algae biomass from the diatom Phaeodactylum tricornutum. Taken together, this work illustrates the versatility of the oxygen electrode-based method for characterizing catalase function in samples with a high degree of complexity and enables the assessment of sample treatment protocols and comparisons between different biological systems related to the skin organ or algae-derived materials as a potential source of skin care ingredients for combating oxidative stress.