Search Results (123)

Background: Postmortem DNA identification of highly decomposed human remains is often limited by the availability and quality of conventional biological samples. Keratinized tissues, such as fingernails, represent a potentially valuable alternative due to their anatomical resistance to environmental degradation, however, their use as primary biological material for DNA profiling remains underreported in forensic practice. Case presentation: We report a case involving the recovery of a highly decomposed body of a missing woman, in which DNA samples were collected from a fingernail and a tooth. DNA extraction was performed using the PrepFiler Forensic DNA Extraction Kit for the fingernail sample and PrepFiler BTA Forensic DNA Extraction Kit for the tooth sample. No usable DNA profile was obtained from the tooth sample; however, the fingernail sample yielded a complete and high-quality STR profile with successful amplification across all 24 loci (GlobalFiler PCR Amplification Kit). Reference buccal swabs from the presumed biological parents were collected for subsequent kinship analysis. Discussion: Kinship analysis based on allele frequencies in the Croatian population resulted in a combined paternity index (CPI) corresponding to a probability of paternity of 99.99999812%, providing strong genetic support for the proposed identity of the deceased. Notably, this is the first documented forensic case in Croatia in which nail material served as the primary—and ultimately successful—biological sample for postmortem identification. Conclusions: This case highlights the evidentiary value of fingernails as a robust, accessible, and forensically valid DNA source in postmortem identification, particularly in cases of advanced decomposition where conventional biological materials are unavailable or degraded. Further studies involving larger sample sets and diverse postmortem conditions are needed to support the broader implementation of nail material in routine forensic identification workflows, particularly within the Croatian medico-legal context. Full article

The increasing use of electronic cigarettes (e-cigarettes) highlights the need for accessible and reliable biomarkers to assess nicotine exposure. Fingernails represent a non-invasive and stable keratin matrix capable of capturing the long-term incorporation of xenobiotics such as cotinine, the primary metabolite of nicotine. This study aimed to optimise cotinine extraction from fingernails using Response Surface Methodology (RSM) with a central composite design prior to quantification by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Three extraction variables were evaluated: NaOH concentration, extraction temperature, and extraction time. Numerical optimisation identified the optimal conditions as 3.74 M NaOH, 50 °C, and 40 min, yielding a predicted recovery of 84.06% with a high desirability value of 0.973. The calibration curve demonstrated excellent linearity (R² = 0.9998), with a limit of detection of 14.5 µg kg⁻¹ and a limit of quantification of 43.8 µg kg⁻¹. The RSM model exhibited strong predictive performance, with an R² of 0.9990, an adjusted R² of 0.9982, and a predicted R² of 0.9958, supported by a non-significant lack of fit and robust residual diagnostics. Application of the optimised protocol to real fingernail samples successfully differentiated e-cigarette smokers from non-smokers based on characteristic cotinine-associated FTIR spectral features and quantitative measurements, demonstrating the practical utility of the proposed method. Overall, this study establishes a rapid, chromatography-free, and cost-effective analytical approach for monitoring long-term nicotine exposure using keratin-based matrices. Full article

Background and Objectives: Nasopharyngeal carcinoma (NPC) displays marked geographic and histopathological heterogeneity, and prognostic determinants in non-endemic regions remain incompletely defined. This study aimed to evaluate the impact of clinicopathological characteristics and treatment modalities on survival outcomes among patients with stage II–IVA NPC treated with curative intent at a single tertiary cancer center. Materials and Methods: A retrospective analysis was conducted on 81 consecutive patients with histologically confirmed NPC treated between 2000 and 2022. Demographic, clinical, and treatment parameters were extracted from institutional records. Survival outcomes—including disease-free survival (DFS), locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and overall survival (OS)—were estimated using the Kaplan–Meier method and compared using the log-rank test. Prognostic variables identified in univariate analysis were further assessed by multivariable Cox proportional hazards regression (Cox’s model). Results: The cohort included 59 men (72.8%) and 22 women (27.2%), with a median age of 50.8 years (range, 19–78). Most patients presented with locally advanced disease (T3–T4, 53.1%; N2, 60.5%; stage III–IVA, 87.7%). Non-keratinizing undifferentiated carcinoma (World Health Organization [WHO] type III) was the predominant histology (71.6%), followed by the non-keratinizing differentiated subtype (17.3%). Median DFS and OS were 94.6 and 139.4 months, respectively. According to the univariate analysis, histological subtypes and a family history of cancer were significantly associated with DFS, whereas comorbid systemic disease showed an unexpected association with longer DMFS. The multivariable Cox model identified the histological subtype as an independent predictor of disease recurrence (HR = 2.23, 95% CI: 1.00–4.94; p = 0.049). For OS, both histological subtype (HR = 2.40, 95% CI: 1.10–5.25; p = 0.029) and age at diagnosis (HR = 1.05, 95% CI: 1.02–1.09; p = 0.005) were independent adverse prognostic factors. Conclusions: In this long-term, single-center study from a non-endemic region, histological subtype emerged as the most powerful determinant of prognosis, significantly influencing both DFS and OS. Patients with non-keratinizing undifferentiated (WHO type III) carcinoma demonstrated superior outcomes compared with those with differentiated histology. Additionally, increasing age at diagnosis was independently associated with poorer OS. In contrast, inflammatory and nutritional biomarkers, the Pan-Immune–Inflammation Value (PIV) and the Prognostic Nutritional Index (PNI), showed no prognostic significance. These findings underscore the continued prognostic relevance of histopathologic classification and age and highlight the need for large-scale, standardized studies integrating Epstein–Barr virus (EBV) status and host-related factors in non-endemic NPC populations. Full article

Agricultural and agro-industrial residues are increasingly recognized as sustainable, low-cost feedstocks for high-performance biomedical materials. This review critically examines the translational potential of polysaccharides, proteins, inorganic compounds, and phytochemical-rich extracts derived from agro-waste, highlighting their chemical features, structure–function relationships, and application-specific readiness. Polysaccharides such as nanocellulose, pectin, and chitosan emerge as the most advanced biopolymer platforms, particularly in wound healing, drug delivery, and 3D-printed scaffolds. Protein-derived materials—including collagen, gelatin, keratin, and soy protein—show strong promise in regenerative medicine, though challenges in mechanical stability and batch reproducibility remain. Inorganic phases such as hydroxyapatite and silica obtained from eggshells, rice husk ash, and marine shells demonstrate high bioactivity, with dental and bone applications approaching clinical translation. Finally, fruit-residue phytochemicals provide multifunctional antioxidant and antimicrobial enhancements to composite systems. By integrating material chemistry, processing strategies, and translational considerations, this review outlines the current state, challenges, and future perspectives for advancing agro-waste-derived biomaterials within a circular bioeconomy. Full article

Egg products are a convenient and safe form of eggs, possessing valuable nutritional and functional properties. The egg processing industry is responsible for the enormous amounts of biomass in the form of animal by-products (ABPs). According to EU legislation, the ABPs are under strict control from the formation to the disposal of biomass, as they carry a risk to the ecosystem and public health. For this reason, restrictions have been introduced on their use after disposal, ranging from bioactive applications in medical, cosmetic, and pharmaceutical products, as well as feed. The shells are subject to special conditions for processing and use. The by-products of egg breaking are divided into solid (eggshells and eggshell membranes) and liquid (technical albumen) by-products. The biological value is determined by the composition, which varies significantly across the by-products. In the context of the circular economy, all egg by-products contain valuable substances that can be used in food and non-food industries. First, eggshells are the leading by-product, composing 95% of the inorganic substance calcium carbonate, which, after processing, can be used in agriculture, food and feed industries, and medicine. Second, there is a liquid by-product containing proteins from the egg white and a small part of fats from the yolk. Literature data on this by-product are scarce, but there is information about its use as a feed additive, while the extracted and purified proteins can be useful in pharmacy. Egg membranes constitute only 1% of the egg mass, but humanity has long known about the benefits of collagen, keratin, and glycosaminoglycans, including hyaluronic acid, which compose this material. The processed membranes can be used as a food additive, in cosmetics, medicine, or pharmacy, just like other egg by-products mentioned above. This literature review focuses on the possible methods and techniques for processing by-products and their potential application. The literature sources in this review have been selected according to their scientific and practical applicability. The utilization of these by-products not only reduces the impact on the environment but also facilitates the creation of value-added materials. Full article

The valorization of poultry feather waste as a sustainable source of keratin aligns with circular economy principles and offers an environmentally responsible solution to managing agro-industrial residues. In this study, an eco-friendly alkaline oxidative extraction method using hydrogen peroxide (H₂O₂) was investigated for recovering keratin from chicken feathers. The process was optimized through a Taguchi experimental design to enhance both extraction efficiency and protein regeneration. Four critical parameters, H₂O₂ concentration, pH, temperature, and extraction time, were studied at three levels each using an L9 orthogonal array. Their effects on solubilization and regeneration yields were systematically evaluated. Statistical analysis revealed that pH and H₂O₂ concentration had the most significant influence on keratin yield. The optimal conditions for maximum solubilization (2 M H₂O₂, pH 12, 75 °C, 1.5 h) yielded high extraction efficiency, whereas a lower H₂O₂ concentration (1 M) favored better regeneration, indicating that excessive oxidation may compromise protein reassembly. Regression models and ANOVA confirmed the statistical significance of these findings, with R² values of 94.25% for solubilization and 78.23% for regeneration. The extracted keratin maintained essential structural features, as verified through subsequent characterization. This work not only improves the sustainability and effectiveness of keratin recovery but also establishes a statistically robust optimization approach. The methodology and insights provided can support future efforts in developing high-quality keratin-based biomaterials for biomedical, cosmetic, or environmental applications. Full article

Wound healing dysregulation often results in visible scarring with significant psychological impact, particularly affecting individuals with darker skin phototypes. This study investigates the efficacy of an aqueous extract of Australian Jellybush honey (Leptospermum polygalifolium) in improving scar appearance across diverse skin tones. Our research demonstrated the extract reduced IL-8 production by 42%, decreased reactive oxygen species by 14.6%, and increased pro-collagen I synthesis by 28%. Ex vivo experiments revealed a 44% increase in neo-epidermal tongue length after 10 days while gene expression analysis showed coordinated wound healing through timed modulation of key markers such as filaggrin, matrix metalloproteases, keratins. In a double-blind clinical study involving 21 volunteers (phototypes II–VI) with acne scars, 8-week application of 2% Jellybush honey extract improved skin homogeneity by 15%, reduced scar surface area by 3% and decreased atrophic and hypertrophic scars dimensions by 9% and 16%, respectively, versus placebo. These improvements were consistent across all phototypes, including V-VI. Jellybush honey extract offers a promising approach for scar management through balanced modulation of wound healing pathways across all skin phototypes. Full article

This study presents the development of antibacterial electrospun nanofibrous mats composed of keratin and polyethylene oxide, incorporating Echinacea purpurea L. (EchP) and green-synthesized silver nanoparticles (bioAgNPs) produced using EchP extract. The successful synthesis of bioAgNPs was confirmed by colorimetric analysis, FTIR, XRD, and TEM. In vitro assays demonstrated antibacterial activity against both Gram-positive and Gram-negative bacteria at ~0.6 µg/mL. Keratin, extracted from sheep wool, retained partial native structure, supporting biocompatibility and cellular regeneration. Incorporation of EchP or bioAgNPs reduced solution viscosity by 25–45%, significantly affecting mat morphology and shifting fiber diameters toward the 50–100 nm range. Quantitative phytochemical analysis, conducted via UV-Vis spectrophotometry, showed 2–3 times higher release of tannins and phenolic compounds compared to hydroxycinnamic acid derivatives and flavonoids. Keratin electrospun mats with bioAgNPs exhibited about 1.5-fold lower polyphenol release, confirming the dual role of polyphenols as electron donors in Ag⁺ bioreduction and as stabilizers. Full article

Introduction: Nasopharyngeal carcinoma (NPC) is a distinct malignancy of the head and neck with high prevalence in endemic regions and a strong association with Epstein–Barr virus (EBV). In locally advanced stages, neoadjuvant chemotherapy (NAC) followed by chemoradiotherapy improves outcomes, but response rates vary. Identifying early predictors of NAC response is essential for guiding personalized treatment strategies. This study aims to assess whether baseline [¹⁸F]FDG PET/CT parameters can predict NAC response in NPC patients. Methods: In this retrospective study, 27 patients with histologically confirmed, locally advanced (stage III) NPC underwent baseline [¹⁸F]FDG PET/CT prior to NAC between 2015 and 2023. Quantitative PET parameters including SUVmax, SUVmean, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were extracted from the primary tumor. NAC response was assessed using RECIST 1.1 criteria and classified as responders (CR + PR) or non-responders (SD + PD). Group comparisons were performed using Student’s t-test. ROC analysis was used to identify optimal cut-off values. A p-value < 0.05 was considered significant. Results: The cohort included 20 males and 7 females (mean age: 60.8 ± 15.2 years). The predominant histotype was undifferentiated non-keratinizing carcinoma (92.6%). A total of 19 patients (70.4%) responded to NAC. Responders had significantly lower baseline SUVmax (10.9 ± 4.8 vs. 15.8 ± 4.1, p = 0.021), MTV (16.2 ± 12.4 vs. 27.8 ± 19.5 cm³, p = 0.045), and TLG (128.6 ± 98.2 vs. 218.7 ± 152.4, p = 0.038). SUVmean was also lower in responders (6.1 ± 2.1 vs. 9.3 ± 2.8), although not statistically reported. ROC analysis identified SUVmax > 12.5 and MTV > 20.0 cm³ as thresholds associated with poor NAC response. Conclusions: Baseline metabolic parameters from [¹⁸F]FDG PET/CT, particularly SUVmax and MTV, may assist stratification of NAC response in nasopharyngeal carcinoma. These biomarkers may facilitate pre-treatment stratification and guide more personalized therapeutic approaches. However, the limited sample size may affect the generalizability of these findings, and larger prospective studies are needed to confirm the results. Full article

Although ridge preservation procedures have been shown to prevent post-extraction bone loss, the effectiveness of using a flap or flapless surgical approach remains unclear. The aim of the study was to compare the mentioned above alveolar ridge preservation procedures in the esthetic region of maxilla. Twenty-nine patients were randomly assigned to receive flap (n = 14) or flapless (n = 15) alveolar ridge preservation procedure. Sockets were grafted with alloplastic biomaterial, then covered with a collagen membrane in both groups. Clinical examinations were performed over a 6-month observation period and radiological (CBCT) examination was conducted before and 6 months after treatment. For both after flap and flapless procedures, there was a reduction in interdental papillae height and keratinized tissue width, increase in buccal soft tissues thickness with a decrease in radiological buccal bone plate width, decrease in radiological buccal and lingual plate height (significantly for the flapless group) and radiological alveolar process width reduction (significantly in flapless group at the height of 5 mm and 7 mm from the bottom of the socket). A decrease in the radiological buccal bone plate width was observed, where the further measuring point was from the bottom of the alveolus. In the mucoperiosteal flap preparation, group buccal bone plate width reduction at the height 3 mm, 5 mm and 7 mm was significant and in the flapless group a significant decrease was observed from 5 to 9 mm from the bottom of the socket. Despite ridge preservation, there is soft tissue thickening and a decrease in bone height and width regardless of the flap/flapless method used. Full article

Skin aging causes reduced hydration, elasticity, and increased wrinkles. Recent safety and compliance concerns over oral collagen supplements have increased interest in plant-based alternatives like Hibiscus sabdariffa with antioxidant and anti-aging properties. However, clinical evidence regarding its efficacy remains limited. We aimed to evaluate the effects of this plant-based collagen alternative (VC-H1, Hibiscus Enzyme Extract) supplement on skin hydration, transepidermal water loss (TEWL), desquamation, elasticity, and wrinkle reduction in photoaged individuals. A randomized, double-blind, placebo-controlled clinical trial was conducted with 98 participants (aged 35–60 years) presenting with dry skin and periorbital wrinkles. Participants randomly received 1.5 g/day of VC-H1 or placebo for 12 weeks. Skin hydration, TEWL, deep moisture, keratin index, elasticity, and wrinkle parameters were assessed at baseline, 6 weeks, and 12 weeks. VC-H1 supplementation significantly increased skin hydration, reduced the TEWL and keratin index, and improved deep moisture content for those receiving it compared with the controls. Wrinkle depth significantly decreased, and skin elasticity also improved. Those in the VC-H1 group showed greater overall improvement than those in the control group. Oral VC-H1 supplementation significantly improved skin hydration, elasticity, and wrinkle reduction, suggesting its potential as a plant-based alternative to traditional collagen supplements for skin rejuvenation. Full article

Keratin, a fibrous structural protein, has been employed as a biomaterial for hemostasis and tissue repair due to its structural stability, mechanical strength, biocompatibility, and biodegradability. While extensive research has focused on developing scaffolds using keratin extracted from various sources, no studies to date have explored the use of keratin derived from human nail clippings. In this study, keratin was extracted from human nail clippings using the Shindai method and used to fabricate and compare two types of scaffolds for bone tissue engineering via the freeze-drying method. The first scaffold consisted of keratin combined with gelatin (KG), while the second combined keratin, gelatin, and hydroxyapatite (HAp) (KGH), the latter synthesized from blood cockle clam shells using the wet precipitation method. Physicochemical characterization and surface morphology analysis of keratin and both scaffolds showed promising results. Tensile strength testing revealed a significant difference in Young’s modulus. The KG scaffold exhibited higher porosity, water uptake, and water retention capacity compared to the KGH scaffold. In vitro biocompatibility studies revealed that the KGH scaffold supported higher cell proliferation compared to the KG scaffold. This study demonstrates the potential of using human nail-derived keratin in composite scaffold fabrication and serves as a foundation for future research on this novel biomaterial source. Full article

The poultry industry produces significant quantities of keratin-rich waste, primarily feathers, whose traditional disposal methods—incineration or chemical treatment—result in environmental damage and resource depletion. This research introduces a sustainable biotechnological method for the valorization of feather waste utilizing Gordonia alkanivorans S7, an actinomycete strain extracted from petroleum plant sludge. This is the inaugural publication illustrating keratinolytic activity in the Gordonia genus. The optimization of the degradation process via the Taguchi approach led to the effective biodegradation of untreated home chicken feathers, achieving dry mass loss of up to 99% after 168 h in a mineral medium. The agricultural potential of the obtained keratin hydrolysate, which was high in organic components (C 31.2%, N 8.9%, H 5.1%, and S 1.7%), was assessed. Phytotoxicity tests demonstrated that the feather hydrolysate led to better growth of the indicator plants—Sorghum saccharatum and Lepidium sativum. The highest values of root growth stimulation were 26% for S. saccharatum and 31% for L. sativum, at a dose of 0.01%. Shoot growth stimulation was noted only for L. sativum, reaching 38% (0.01%), 53% (0.05%), and 37% (0.1%), as compared to the control sample. These results demonstrate the process’s combined economic and environmental benefits, providing a fresh approach to the production of bio-based plant biostimulants and sustainable keratin waste management. Full article

Keratin-made biomaterials, including feathers, are considered a protein-rich bioresource due to their intrinsic properties, including biocompatibility, biodegradability, mechanical resistance, and biological abundance. Beta-keratin exists as an insoluble stringy protein due to the high presence of disulfide cross-links, and as a result, it is mechanically stable and resistant to enzymatic digestion. Because of this, it is not easily decomposed, and this has made the application of feathers difficult. In this study, after dissolving feathers in NaOH, sodium sulfide, and 2-Mercaptoethanol (2-ME), the relative molecular mass of beta-keratin was calculated. Thin-layer chromatography was also used to display proteins with lower molecular weights. The antioxidant activities of the samples were evaluated by Fe-chelating and free radical scavenging tests with 2,2-diphenyl-1-picrylhydrazyl (DPPH). To investigate the effect of blocking thiol groups on the antioxidant activity of dissolved keratin, iodoacetamide and H₂O₂ were used. According to the three methods—(A) sodium hydroxide, (B) sodium sulfide, and (C) urea and 2-ME—used to extract and dissolve the feathers, method C caused the least change in the chemical structure of keratin molecules. Method A destroyed the primary structure of keratin and drastically reduced its molecular mass, but method B caused a drastic increase in the molecular mass from 9.6 kDa to higher masses, due to intermolecular bonds. For the keratin molecules dissolved by method C, the Fe-chelating activity was 93.18% and free radical scavenging was 77.45%. Blocking the thiol group with iodoacetamide initially reduced the free radical scavenging activity with DPPH by 42%, but blocking it with H₂O₂ did not affect this activity. Also, blocking of the thiol group did not initially affect Fe-chelating activity and free radical scavenging activity. After a kinetic study of the activities, an interesting observation was that both blocking agents had negative effects on radical scavenging activity, but had positive effects on Fe-chelating activity. This indicates the complexity of the role of disulfide bonds in keratin’s antioxidant behavior types. According to the observed antioxidant activities, it can be expected that beta-keratin extracted from chicken feathers is a suitable candidate for application in industrial, pharmaceutical, and health applications. Full article

Background: Our aim was to assess the expression profiles of the messenger RNA (mRNA) expression profiles of stem-cell genes (POU5F1, NANOG) and pancreatic progenitor genes (CK19, HES1, INS, PDX1) in peripheral-blood mononuclear cells (PBMCs) in selected neoplastic pancreatic diseases, such as cancer and neuroendocrine tumors, to identify neoplastic disease markers in the pancreas. Methods: In this study, 49 patients diagnosed with pancreatic neoplastic diseases (37 with cancer and 12 with neuroendocrine tumors) and 34 control patients, all of whom were hospitalized at a tertiary center, were enrolled. Venous blood samples were collected from the participants, and RNA was extracted from PBMCs. The mRNA expression levels of six stem-cell and pancreatic progenitor markers— POU5F1 (POU class 5 homeobox 1), NANOG, CK19 (keratin 19), HES1 (HES family bHLH transcription factor 1), INS (insulin), and PDX1 (pancreatic and duodenal homeobox 1)—were quantified via real-time quantitative PCR. The data were statistically analyzed to explore associations between gene-expression levels and various clinical, biochemical, and morphological parameters (including full blood count, Ca 19-9, weight, height, and BMI) via the Kruskal–Wallis test, Mann–Whitney U test, and Spearman rank correlation coefficient. Results: The results revealed that the expression of the gene associated with early stem cells, NANOG (median= 0.002, p = 0.03), as well as the genes encoding insulin INS (median = 0.004, p = 0.02) and CK19 (median 0.0003, p = 0.005), was significantly elevated in patients with pancreatic cancer. However, the gene-expression levels in patients with neuroendocrine tumors did not exhibit statistically significant differences compared to those observed in the control group. Additionally, no significant differences in gene expression were observed among patients at different stages of pancreatic cancer. Furthermore, CK19 overexpression was found to be positively correlated with inflammatory markers, specifically C-reactive protein (CRP) and WBC, in patients with pancreatic cancer. Conclusions: An elevated mRNA expression of specific stem and pancreatic progenitor genes (NANOG, INS, CK19) in PBMCs may serve as a potential markers for pancreatic cancer, reflecting the disease’s interplay with systemic inflammation. Full article