Incidence of different types of cancer in the follow-up period after primary diagnosis and treatment of melanoma. Single-centre 4-year follow-up on a population of 709 patients.

Introduction: Follow-up plays a key role in melanoma management, especially in the first years after diagnosis. During this period it is crucial to assess possible recurrence, progression of the disease or treatment complications. An important aspect is also the possibility of formation of new primary foci or other skin cancers. Aim: To assess the coincidence of skin lesions and cancers among the melanoma patients. Material and methods: Patients treated in the Comprehensive Cancer Centre between 2019 and 2022 were retrospectively analysed for occurrence of skin lesions diagnosed during the follow-up, and confirmed by biopsy. The lesions considered included skin cancers, dysplastic nevus and actinic keratosis. Results: In 100 (14%) out of 709 enrolled patients, 184 lesions were diagnosed. In 7 patients it was melanoma, in 49 BCC, and in 16 SCC. Dysplastic nevus and actinic keratosis were excised in 28 and 14 patients, respectively. More than one site of the skin lesion was observed in 39 patients, and more than one type of the lesion in 13 patients. Patients with lesions were on average 8.6 years older (p < 0.001), had less advanced tumours (p = 0.010), and primary melanoma was more often located on the head and neck (p = 0.056). Conclusions: Among melanoma patients, particular attention must be paid to, apart from early detection of melanoma recurrence and progression, the occurrence of new primary foci or independent skin cancers.

An analysis of clinical effectiveness of electrochemotherapy in the treatment of advanced metastatic malignant melanoma performed in the eastern part of Central Europe: a single-centre experience.

Introduction: Patients with cutaneous malignant melanoma (MM), in case of non-resectability of the lesions, have only a limited pool of the available treatment options. In recent years especially electrochemotherapy (ECT) has become an increasingly important therapy in locoregionally advanced MM. Aim: In this study an analysis of the ECT treatment of locoregionally advanced malignant melanoma was presented. Material and methods: Six ECT cycles in 5 patients were performed in the Wroclaw Comprehensive Cancer Centre. Treatment response, long-term observation, technical data downloaded from electroporator and photographs taken before and after the ECT were assessed in the analysis. Results: In total, 200 nodules in 5 patients were treated with ECT in palliative intent. After 5 out of 6 ECT cycles, the particular clinical response has been observed. Four patients with primary unresectable lesions underwent 11 surgeries of the cutaneous metastases. In long-term follow-up in 2 patients, of whom one died 19 months after the ECT, the disease progressed and in another two, no recurrence was observed. Conclusions: ECT is an encouraging therapy for patients in whom the recurrent cutaneous melanoma cannot be treated with other methods, however, access to this method in eastern part of Central Europe is limited. The presented study seems to confirm the usefulness of this palliative approach in a specific group of patients suffering from cutaneous MM.

The report and analysis concerning the usefulness of basic telemedicine tools in the skin cancer diagnostic screening process during COVID-19 pandemics.

Introduction: A rapid spread of the emerging COVID-19 pandemic limited the availability of professional medical advice. As a result, a significant increase in the number of undiagnosed and chronically ill patients without medical care was noticed. In reaction to the urgent need, the telemedical consultation, instead of the classical form, may be introduced as a vulnerable tool in preclinical evaluation of patients with potentially malignant skin lesions. Aim: In this study the results of the implementation of telemedical consultation programme with the intention to early detect the skin cancers in patients who, due to the COVID-19 pandemic, could not undergo the standard consultation was presented. Material and methods: The programme of remote dermatological consultation, which was introduced on 1 June 2020, covered all patients who had no possibility or will to visit the standard healthcare units. In case of suspicion of life-threatening skin lesions patients were invited for additional diagnostics or surgery. Obtained data, including demography, age, surgery description and pathomorphological examination were descriptively analysed. Results: In total, 80 consecutive patients were enrolled during the screening programme. In total, 31 lesions in 25 patients were excised. In this group there were 10 serious diagnoses including 5 cases of basal cell carcinoma, melanoma in situ and dysplastic nevi. Moreover, another 10 patients were referred to other specialists or specific recommendations were advised. Conclusions: An alternative track using teledermatology for patients with skin diseases was successfully introduced under the specific conditions of epidemiologic danger. Despite its disadvantages teledermatology enabled the diagnosis and treatment in a significant number of serious cases.

Porphyrin Based 2D-MOF Structures as Dual-Kinetic Sorafenib Nanocarriers for Hepatoma Treatment.

The existing clinical protocols of hepatoma treatment require improvement of drug efficacy that can be achieved by harnessing nanomedicine. Porphyrin-based, paddle-wheel framework (PPF) structures were obtained and tested as dual-kinetic Sorafenib (SOR) nanocarriers against hepatoma. We experimentally proved that sloughing of PPF structures combined with gradual dissolving are effective mechanisms for releasing the drug from the nanocarrier. By controlling the PPF degradation and size of adsorbed SOR deposits, we were able to augment SOR anticancer effects, both in vitro and in vivo, due to the dual kinetic behavior of SOR@PPF. Obtained drug delivery systems with slow and fast release of SOR influenced effectively, although in a different way, the cancer cells proliferation (reflected with EC50 and ERK 1/2 phosphorylation level). The in vivo studies proved that fast-released SOR@PPF reduces the tumor size considerably, while the slow-released SOR@PPF much better prevents from lymph nodes involvement and distant metastases.

The different expression of key markers on urothelial holoclonal, meroclonal, and paraclonal cells in in vitro culture.

Urothelial cell populations which differ in morphology and proliferation capacities can be isolated from the urinary bladder. The goal of this study was to analyze a clonal, proliferative, and self-renewing potential of porcine urothelial cells and to compare expression of selected adhesion and tight junction molecules, urothelial and stem cell markers for the urothelial clone types. Urothelial cells were isolated from 10 porcine urinary bladders. Three different clone types: holoclone-, meroclone-and paraclone-like colonies were identified based on their morphology. To characterize and compare the urothelial clones the immunofluorescent stains were performed. Expression of pancytokeratin (PanCK), Ki-67 and p63 was higher for holoclone- like cells compared to meroclone-and paraclone-like cells (P < 0.05). Meroclone-like cells expressed higher levels of p63 compared to paraclone- like cells (P < 0.05). The level of Ki-67 and PanCK for meroclone- and paraclone- like cells was comparable (P > 0.05). ß1 and ß4 integrins were not expressed. Expression of zonula occludens-1 (ZO-1) in cell-cell junctions for paraclone-, meroclone-and holoclone-like cells was 17.6 ± 0.6, 14.7 ± 0.5, and 16.1 ± 0.4, respectively. The results of actin filaments (F-actin) expression were 253,634 ± 6,920 for meroclone-like cells, 198,512 ± 7,977 for paraclone-like cells and 133,544 ± 3,169 for holoclone-like cells. Three urothelial cell types with differing features can be isolated from the bladder. Holoclone-like cells are the richest in stem cells and should be used in further studies for construction of neo-bladder or neo-conduit using tissue engineering methods.

Overall clinical and trichoscopic analysis performed in patients who underwent pressurized intraperitoneal aerosol chemotherapy (PIPAC) treatment for peritoneal carcinomatosis - initial trial preliminary report.

INTRODUCTION: Cutaneous adverse events are among the remaining problematic issues of current oncology. The term peritoneal carcinomatosis (PC) refers to the advanced cancer stage. The innovative treatment of PC includes the use of pressurized intraperitoneal aerosol chemotherapy (PIPAC). AIM: To present a preliminary report from an initial trial aimed at an overall clinical and trichoscopic analysis performed in patients who underwent PIPAC treatment due to PC. MATERIAL AND METHODS: For all steps of this study we obtained the consent of the local bioethics commission #KB 196/2018. Three different hair assessment methods were used in our study: 1) general clinical and patient self-feeling assessment; 2) hair pull test; 3) and trichoscopic analysis. RESULTS: No hair or scalp disorders were noted in the observation period. In the self-feeling test assessment the vast majority recognized their hair as being of comparable quality or even better in quality compared to previous forms of chemotherapy they had undergone. In all patients we observed a reduction of hair loss in the pull test in the hospitalization period. In trichoscopic analysis we found all determinants and signs of hair disorders in the assessed group. CONCLUSIONS: The PIPAC is safe and is not a burdensome or aggressive form of therapy, especially according to the very important factors influencing the potential quality of hair and hair loss. The authors, however, realize that to obtain comprehensive results and evaluate this novel and promising method we need to perform more research without any limitations like those in our study.

Stem cells and differentiated cells differ in their sensitivity to urine in vitro.

Urinary tract regeneration using tissue engineering is one of the most challenging issues in the field of reconstructive urology. Cells seeded on scaffold are exposed to urine immediately after the implantation. The outcome of urinary bladder regeneration is depended on the ability of these cells to survive, proliferate, and regenerate. The aim of this study was to compare a sensitivity of three different cell lines to urine in vitro. Three different cell lines were isolated from porcine bladder (urothelial cells, UCs and smooth muscle cells, SMCs) and adipose tissue (adipose-derived stem cells, ADSCs). Cell viability (MTT assay), proliferation (real-time cell analysis using xCELLigence system) and apoptosis/necrosis (flow cytometry) were analyzed after exposition to urine. ADSCs were the most sensitive to urine compared to two other tested cell lines. Among the bladder cell lines the UCs were more resistant to urine than SMCs. Twenty four hour incubation of UCs, SMCs, and ADSCs with urine lead to ∼40%, ∼70%, and ∼90% reduction of their viability, respectively. The mechanism of urine mediated cytotoxicity differed depending on the tested cell type. Urothelial and SMCs seems to be more suitable for urinary bladder regeneration compared to mesenchymal stem cells, however, these cells have limited application especially in the case of urinary bladder cancer.

Does the presence of sentinel lymph node macrometastases in breast cancer patients require axillary lymph node dissection?-Single-center analysis.

According to the current guidelines on treatment of breast cancer patients, identification of metastases in the sentinel lymph node (SLN (+)) is not an absolute indication for necessary axillary lymph node dissection (ALND). In our study, we present long-term outcomes of treatment among SLN(+) patients referred for conservative treatment, for example, no further ALND. A total of 3145 breast cancer patients subjected to sentinel lymph node biopsy (SLNB) between November 2008 and June 2015. SLN metastases were identified in 719 patients (22.9%). Locoregional recurrences and distant metastases as endpoints were distinquished. The mean follow-up time for patients after ALND was 36.2 months (6-74 months); 18.8 months (6-38 months) for patients with SLN macrometastases without ALND; and 34.0 months (6-74 months) for patients with micrometastases. Adjuvant ALND was performed in 626 of SLN(+) patients. Conservative treatment was applied in the remaining 93 cases. Among SLN(+) patients without adjuvant ALND, there was one case of recurrence (1.07%). In the group of patients without SLN, metastases recurrence was noted in 32 patients (1.32%). Among SLN(+) patients diagnosed with macrometastases, recurrence concerned 2.01% of analyzed cases (all subjected to ALND). Lack of radical surgical treatment in SLN(+) breast cancer patients did not lead to worsening long-term outcomes. In the occurrence of macrometastases to the sentinel lymph node, abandoning completion axillary lymph node dissection might be a reasonable option. However, it would require continuation of current research, preferably involving a clinical trial.

Vascularization Potential of Electrospun Poly(L-Lactide-co-Caprolactone) Scaffold: The Impact for Tissue Engineering.

BACKGROUND Electrospun nanofibers have widespread putative applications in the field of regenerative medicine and tissue engineering. When compared to naturally occurring collagen matrices, electrospun nanofiber scaffolds have two distinct advantages: they do not induce a foreign body reaction and they are not at risk for biological contamination. However, the exact substrate, structure, and production methods have yet to be defined. MATERIAL AND METHODS In the current study, tubular-shaped poly(L-lactide-co-caprolactone) (PLCL) constructs produced using electrospinning technology were evaluated for their potential application in the field of tissue regeneration in two separate anatomic locations: the skin and the abdomen. The constructs were designed to have an internal diameter of 3 mm and thickness of 200 µm. Using a rodent model, 20 PLCL tubular constructs were surgically implanted in the abdominal cavity and subcutaneously. The constructs were then evaluated histologically using electron microscopy at 6 weeks post-implantation. RESULTS Histological evaluation and analysis using scanning electron microscopy showed that pure scaffolds by themselves were able to induce angiogenesis after implantation in the rat model. Vascularization was observed in both tested groups; however, better results were obtained after intraperitoneal implantation. Formation of more and larger vessels that migrated inside the scaffold was observed after implantation into the peritoneum. In this group no evidence of inflammation and better integration of scaffold with host tissue were noticed. Subcutaneous implantation resulted in more fibrotic reaction, and differences in cell morphology were also observed between the two tested groups. CONCLUSIONS This study provides a standardized evaluation of a PLCL conduit structure in two different anatomic locations, demonstrating the excellent ability of the structure to achieve vascularization. Functional, histological, and mechanical data clearly indicate prospective clinical utilization of PLCL in critical size defect regeneration.

Air pollution, UV irradiation and skin carcinogenesis: what we know, where we stand and what is likely to happen in the future?

The link between air pollution, UV irradiation and skin carcinogenesis has been demonstrated within a large number of epidemiological studies. Many have shown the detrimental effect that UV irradiation can have on human health as well as the long-term damage which can result from air pollution, the European ESCAPE project being a notable example. In total, at present around 2800 different chemical substances are systematically released into the air. This paper looks at the hazardous impact of air pollution and UV and discusses: 1) what we know; 2) where we stand; and 3) what is likely to happen in the future. Thereafter, we will argue that there is still insufficient evidence of how great direct air pollution and UV irradiation are as factors in the development of skin carcinogenesis. However, future prospects of progress are bright due to a number of encouraging diagnostic and preventive projects in progress at the moment.

The use of stem cells in aesthetic dermatology and plastic surgery procedures. A compact review of experimental and clinical applications.

The aim of this paper was to collect currently available data related to the use of stem cells in aesthetic dermatology and plastic surgery based on a systemic review of experimental and clinical applications. We found that the use of stem cells is very promising but the current state of art is still not effective. This situation is connected with not fully known mechanisms of cell interactions, possible risks and side effects. We think that there is a big need to create and conduct different studies which could resolve problems of stem cells use for implementation into aesthetic dermatology and plastic surgery.

Changes of Langerhans cells during skin ageing.

INTRODUCTION: During the process of skin ageing, changes occur in all skin layers and all cells, including the Langerhans cells. AIM: To assess whether any quantitative difference in the number of CD1a+ LC cells/mm2 and HLA-DR+ LC cells/mm2 as well as in their morphological features can be observed during the course of different types of skin ageing. MATERIAL AND METHODS: The study was conducted in a group of 60 women, which was divided into three independent groups: group I with symptoms of menopausal skin ageing, group II with symptoms of photoageing, group III with symptoms of chronological ageing. Skin biopsy samples were taken from the pre-auricular region from all of the participants. The number of CD1a+ LC cells/mm2 and HLA-DR+ LC cells/mm2 as well as their morphological features were evaluated. RESULTS: The frequency of CD1a+ LC and HLA-DR+ LC in all the studied groups was diverse. In groups I and III, the LC with large cell bodies and long, multi-branched processes were the majority. In group II, the LC had small cell bodies and their processes were mainly short and unbranched. CONCLUSIONS: The obtained results indicate the presence of quantitative and morphological changes of the CD1a+ LC and HLA-DR+ LC during the course of different types of skin ageing.

Isolation, expansion and characterization of porcine urinary bladder smooth muscle cells for tissue engineering.

BACKGROUND: A key requirements for therapy utilizing the tissue engineering methodologies is use of techniques which have the capability to yield a high number of cells, from small tissue biopsy in a relatively short time. Up to date there was no optimal methods of isolation and expansion of urinary bladder smooth muscle cells (UB-SMCs). The aim of this study was to compare isolation and expansion techniques of UB-SMCs to select the most repeatable and efficient one. METHOD: Five protocols of porcine UB- SMCs isolation including enzymatic and explant techniques and three expansion techniques were compared. Isolation effectiveness was evaluated using trypan blue assay. Cell phenotype was confirmed by immunofluorescence staining. Proliferation rate was analyzed using MTT and X- Celligence system. Cellular senescence was assessed measuring ß-galactosidase activity. RESULTS: Enzymatic methods using collagenase with dispase (method I) or collagenase only (method III) allowed to isolate much larger number of cells than the methods using trypsin with collagenase (method II) and collagenase after digestion with trypsin (method IV). The success rate of establishment of primary culture was the highest when the isolated cells were cultured in the Smooth muscle Growth Medium-2 (SmGM-2). Expression of the smooth muscle markers- alpha smooth muscle actin and smoothelin was the highest for cells isolated by enzymatic method I and cultured in SmGM-2. There was no significant signs of cell senescence until the 8th passage. CONCLUSION: The most efficient method of establishment of porcine UB-SMCs culture is enzymatic digestion of urinary bladder tissue with collagenase and dispase and culture of isolated cells in SmGM-2. This method was up to 10 times more efficient than other methods used for isolation and culture of UB-SMCs. This is an easy and consistent method for obtaining high numbers of urinary bladder smooth muscle cells.

Optimization of porcine urothelial cell cultures: Best practices, recommendations, and threats.

Many experimental approaches have been conducted in order to isolate urothelial cells from bladder tissue biopsies, but each method described has utilized different protocols and sources of bladder tissue. In this study, we compared the different methods of urothelial cell isolation available in literature together with standardized methods in order to obtain more unified results. Five methods for primary porcine urothelial culture establishment were compared: tissue explants and four enzymatic methods utilizing collagenase II, dispase II, combination of dispase II and trypsin, and trypsin alone. The average number of isolated cells, cell morphology, success of established culture, average number of cells from the first passage, expression of p63 and pancytokeratin and the characterization of urothelial cell growth, and aging were analyzed during the in vitro culture. The method utilizing dispase II was the most efficient and reproducible method for the isolation and culture of porcine urothelial cells when compared to the other tested methods. Urothelial cells obtained by this method grew considerably well and the cultures were established with high efficiency, which enabled us in obtaining a large quantity of cells with normal morphology. Contamination with fibroblasts in this method was the lowest. The utilization of a proper method for urothelial cell isolation is a critical step in the urinary tract regeneration when using tissue engineering techniques. In summary, this study demonstrated that by utilizing the described method with dispase II, a suitable number of cells was achieved, proving the method useful for tissue regeneration.

Is regenerative medicine a new hope for kidney replacement?

The availability of kidney and other organs from matching donors is not enough for many patients on demand for organ transplant. Unfortunately, this situation is not better despite the many of new interesting projects of promoting family, cross or domino transplants. These inexorable global statistics forced medical researchers to find a new potential therapeutic option that would guarantee safety and efficacy for the treatment of ESRD comparable to kidney transplantation. The aim of our review is to summarize the scientific literature that relating to the modern as well as innovative experimental methods and possibilities of kidney regeneration and, in addition, to find whether the regenerative medicine field will be a new hope for curing the patient with renal disease complications. The most important achievements in the field of regenerative medicine of kidney, which were mentioned and described here, are currently cumulated in 4 areas of interest: stem cell-based therapies, neo-kidneys with specially designed scaffolds or cell-seeded matrices, bioartificial kidneys and innovative nanotechnologically bioengineered solutions. Nowadays, we can add some remarks that the regenerative medicine is still insufficient to completely replace current therapy methods used in patients with chronic kidney disease especially with the end-stage renal disease where in many cases kidney transplantation is the only one chance. But we think that development of regenerative medicine especially in the last 20 years brings us more and more closer to solve many of today's problems at the frontier of nephrology and transplantology.

Filling effects, persistence, and safety of dermal fillers formulated with stem cells in an animal model.

BACKGROUND: Research is scarce regarding the effectiveness of dermal fillers containing autologous stem cells. OBJECTIVES: The authors sought to determine the local and systemic effects of adipose-derived stem cells (ADSCs) as a component of dermal fillers in an animal model. METHODS: Wistar rats were injected with 1 of the following dermal fillers: ADSCs combined with hyaluronic acid (ADSC-HA), ADSCs combined with fish collagen (ADSC-COL), HA alone (CONTROL-HA), or COL alone (CONTROL-COL). Fillers were injected into the glabella, dorsum, and chest of each animal. The ADSCs were labeled with PKH26 to assess cell migration. Filling effects (FEs) were measured immediately after injection and at 1.5 months and 3 months after injection. Skin specimens were stained with hematoxylin and eosin to assess localization and persistence of ADSCs. RESULTS: Mean FEs in animals implanted with ADSCs were greater and persisted longer than those of controls. No inflammatory responses were observed in any group. Three months after injection, PKH26-positive cells comprised nearly 70% of cells at the injection site in animals treated with ADSC-HA. PKH26 fluorescence also was detected in the spleen but not in the brain, kidney, or lung. CONCLUSIONS: Stem cells have the potential to improve the aesthetic effects and longevity of dermal fillers.

[Modern biomaterials as hemostatic dressings in kidney nephron sparing surgery (NSS)--murine model. A preliminary report]. / Nowoczesne biomaterialy jako opatrunki hemostatyczne w chirurgii oszczedzajacej miazsz nerki--model zwierzecy. Doniesienie wstepne.

INTRODUCTION: Kidney cancer is now days, one of the main problems in oncological urology. More frequent cases detection of this type of cancer and the implementation of modern methods of treatment, involves the public and good diagnostic radiological imaging methods. Approximately 40% of renal tumors are detected clinically as a changes in T1N0M0 stage. This means that in these patients, surgery can be performed using the method of nephron sparing surgery (NSS), far from consisting the implementation of radical nephrectomy. Unfortunately, despite the saving nature of this type of treatment, NSS methods are associated with local recurrence of tumor formation. Another problem is intra operative bleeding, that's why in order to stop this negative process surgeons currently use hemostatic dressings. Potentially and clinically significant solution could be a combination of this two main problematics points of concern, through the use of modern biomaterials coated on oncostatic substances as a haemostatic dressings, to the prevention of tumor recurrence. AIM OF THE WORK: The aim of this work, was to present preliminary report of the use of advanced biomaterials, as haemostatic dressings in an experimental technique of nephron sparing surgery on an murine model. MATERIAL AND METHODS: In the experiment we use two types of biomaterials and the standard haemostatic dressing used in the nephron sparing surgery (NSS) as a control. We use a polycaprolactone biomaterial obtained by electrospinning. As a second type of biomaterial, we use a homogeneous material with a structure similar to wool, also obtained from medical polycaprolactone by electrospinning. As an murine (in vivo) model in the study, we use 10 C57BL/J mice (with the local ethical committee permission). 8 mice were used in the present study, 2 mice were constituted as a separate control for obtaining the bleeding data. Kidney melanoma cells were implanted under the C57B1/J B16 mouse kidney fibrous capsule, one week before NSS. After 3 weeks the animals were sacrificed for comparison of hemostatic dressings function. RESULTS: Used biomaterials fulfilled their role as a hameostatic dresings. The material (Type I) was convenient and good for suturing. Haemostatic action times were as follows: (Type I) - 30 seconds. (Type III) - 50 seconds. In the control group were also observed, a proper hemostatic function after 30 seconds. In sectional observation was also found in 3 kidneys section preparation samples, a local tumor recurrence and metastasis to the other tissues of the abdomen. CONCLUSION: The tested biomaterials fulfill their hemostatic effect on kidney after NSS, without any significant difference acording to a standard hemostatic dressing used clinically. This data may be a potential factor for use in further studies to determine their continued relevance in the prevention of local tumor recurrence after nephron sparing surgery.

Consensus guidelines for pressurized intraperitoneal aerosol chemotherapy: Technical aspects and treatment protocols.

BACKGROUND: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is increasingly used to treat patients with peritoneal cancer. A recent survey demonstrated considerable diversification of current practice of PIPAC raising issues of concern also regarding safety and efficacy. The study aim was to reach consensus on best practice of PIPAC treatment. METHODS: Current practice was critically discussed during an expert meeting and the available evidence was scrutinized to elaborate a 33-item closed-ended questionnaire. All active PIPAC centers were then invited to participate in an online two-round Delphi process with 3 reminders at least. Consensus was defined a priori as >70% agreement for a minimal response rate of 70%. RESULTS: Forty-nine out of 57 invited PIPAC centers participated in Delphi 1 and 2 (86%). Overall, there was agreement for 21/33 items. Consensus was reached for important aspects like advanced OR ventilation system (91.8%), remote monitoring (95.9%), use of the PRGS (85.7%) and use of a safety checklist (98%). The drug regimens oxaliplatin (87.8%) and cisplatin/doxorubicin (81.6%) were both confirmed by the expert panel. Important controversies included number and location of Biopsies during repeated PIPAC and the combination of PIPAC with additional surgical procedures. CONCLUSION: This consensus statement aims to allow for safe and efficacious PIPAC treatment and to facilitate multi-center analyses of the results. Additional preclinical and clinical studies are needed to resolve the remaining controversies.

Additive manufacturing technologies enabling rapid and interventional production of protective face shields and masks during the COVID-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted through respiratory droplets and contact routes, hence the demand for personal protective equipment (PPE) has increased during the outbreak of coronavirus disease 2019 (COVID-19). Among the most noticeable shortages was the lack of face shields. The urgent demand for PPE induced interdisciplinary cooperation to overcome the shortages, and additive manufacturing proved to be ideal for the crisis situation. OBJECTIVES: To investigate the possibilities of implementing additive manufacturing technologies in the interventional fabrication of protective face shields for medical staff. MATERIAL AND METHODS: An Ender 3 Pro 3D printer was used to print headbands and Cura 4.4 was chosen as the slicing software. Open source face shield designs were downloaded as standard tessellation language (STL) files and compared. Only models with scientific support were taken under consideration. RESULTS: The mean time for producing the headbands tested ranged from 59 min to almost 3 h, depending on the design. After setting up our low budget printer and choosing the Prusa RC 3 protective face shield as the main product, we were able to fabricate about 30 face shields per week at a cost of about €1 each. During 4 weeks, 126 face shields were produced and delivered to various hospital wards, which substantially eased the shortages. CONCLUSIONS: Additive manufacturing enables immediate responses to needs in emergency situations, and allows for mass production of personal protective equipment in a short time due the rapid exchange of data among printer users. Despite the unregulated legal situation and insufficient scientific evidence, such protective equipment has been approved by clinicians and is currently used by medical personnel around the world.