Contact allergy to formaldehyde. Diagnosis and clinical relevance.

Preservatives are biologically active substances mainly used in water-based products to prevent the growth of microorganisms. Most people are exposed to them on a daily basis. Formaldehyde is one of the oldest and most commonly used preservatives. However, it is a well-known contact sensitiser in dermatitis patients. The aims of this work were: i) to investigate the prevalence of contact allergy to formaldehyde using the baseline patch test series; ii) to determine the optimal patch test concentration and dose for formaldehyde; iii) to study the clinical relevance of contact allergy to formaldehyde detected by formaldehyde 2.0% (0.60 mg/cm2) but not by formaldehyde 1.0% (0.30 mg/cm2); iv) to study the effects of low concentrations of formaldehyde on irritant contact dermatitis in formaldehyde-allergic patients; v) to semi-quantify the formaldehyde content in skin care products used by patients with suspected allergic contact dermatitis, and compare this with the declaration of contents; vi) to determine whether formaldehyde-allergic patients are more exposed to formaldehyde in skin care products than dermatitis patients without contact allergy to formaldehyde; vii) to investigate the patterns of concomitant contact allergy to formaldehyde and formaldehyde releasers. The findings were as follows: i) patch testing with 15 μl formaldehyde 2.0% (0.60 mg/cm2) using a micropipette detects significantly more reacting individuals than 1.0% (0.30 mg/cm2), without a high frequency of irritant reactions. ii) individuals who react to formaldehyde 2.0% (0.60 mg/cm2) but not to 1.0% (0.30 mg/cm2) have a significant risk of developing an eczematous reaction when exposed to concentrations of formaldehyde allowed by the EU Cosmetic Directive. iii) daily exposure to low concentrations of formaldehyde is sufficient to exacerbate existing dermatitis in patients with contact allergy to formaldehyde. iv) to assess exposure and clinical relevance in formaldehyde-allergic patients, the patients’ skin care products should be analysed, especially when the labelling of the products does not include formaldehyde or formaldehyde-releasing preservatives

From blood to regenerative tissue : How autologous platelet-rich fibrin can be combined with other materials to ensure controlled drug and growth factor release

Funding Information: This research was funded by the Latvian Council of Science research project No. lzp-2020/1-0054 ?Development of antibacterial autologous fibrin matrices in maxillofacial surgery (MATRI-X)?. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The purpose of this review is to examine the latest literature on the use of autologous platelet-rich fibrin as a drug and growth factor carrier system in maxillofacial surgery. Autologous platelet-rich fibrin (PRF) is a unique system that combines properties such as biocompatibility and biodegradability, in addition to containing growth factors and peptides that provide tissue regeneration. This opens up new horizons for the use of all beneficial ingredients in the blood sample for biomedical purposes. By itself, PRF has an unstable effect on osteogenesis: therefore, advanced approaches, including the combination of PRF with materials or drugs, are of great interest in clinics. The main advantage of drug delivery systems is that by controlling drug release, high drug concentrations locally and fewer side effects within other tissue can be achieved. This is especially important in tissues with limited blood supply, such as bone tissue compared to soft tissue. The ability of PRF to degrade naturally is considered an advantage for its use as a “warehouse” of controlled drug release systems. We are focusing on this concentrate, as it is easy to use in manipulations and can be delivered directly to the surgical site. The target audience for this review are researchers and medical doctors who are involved in the development and research of PRFs further studies. Likewise, surgeons who use PRF in their work to treat patients and who advice patients to take the medicine orally.publishersversionPeer reviewe

Can Our Blood Help Ensure Antimicrobial and Anti-Inflammatory Properties in Oral and Maxillofacial Surgery?

Funding Information: This research was funded by the European Union’s Horizon 2020 research and innovation program under the grant agreement No 857287 and the Latvian Council of Science research project No. lzp-2020/1-0054 “Development of antibacterial autologous fibrin matrices in maxillofacial surgery (MATRI-X)”. Publisher Copyright: © 2023 by the authors.In recent decades, the potential of PRF has been extensively studied. The number of studies about PRF has increased three times since the year 2012, but the full spectrum of its fundamental properties, such as antimicrobial and anti-inflammatory activity, is not clearly described. In oral and maxillofacial surgery, PRF is described in alveolar ridge preservation, orthognathic surgery, cleft lip and palate surgery, maxillary sinus augmentation, and dental implant placement as demonstrating favorable results and its clinical advantages. The structural complexity, inhomogeneous nature, and clotting ability of PRF make its antimicrobial effect evaluation complicated. Nevertheless, most of the used antimicrobial testing methods are based on antibacterial agent diffusion ability in culture media. Because the oral and maxillofacial region is the most frequent area of PRF application, its antimicrobial activity evaluation also prevails in the oral microbiome. PRF’s biological potential is highly dependent on the specific preparation protocol and methodology used; it should be carefully prepared and kept under proper conditions to keep cellular content alive. PRF’s influence on living cells demonstrates a stimulating effect on bone regeneration, and an angiogenetic effect, and it provides anti-inflammatory activity. According to analyzed studies, PRF demonstrated success in oral and maxillofacial surgery in various methods of application. Antibacterial and anti-inflammatory properties were proven by antibacterial activity against different bacterial species, sustained growth factor, sustained release, and cell activity on the material application. Accurately and correctly prepared PRF can ensure antibacterial and anti-inflammatory properties, and it can be a beneficial clinical tool in oral and maxillofacial surgery.publishersversionPeer reviewe

Injectable Platelet-Rich Fibrin as a Drug Carrier Increases the Antibacterial Susceptibility of Antibiotic—Clindamycin Phosphate

Funding Information: Acknowledgments: The authors acknowledge financial support from the Latvian Council of Science research project “Development of antibacterial autologous fibrin matrices in maxillofacial surgery” (MATRI-X) under agreement No. lzp-2020/1-0054. This work was also supported by the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 857287 (BBCE). The authors thank Agnese Brangule for her help with FTIR analysis. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The aim of this study was to investigate the change in clindamycin phosphate antibacterial properties against Gram-positive bacteria using the platelet-rich fibrin as a carrier matrix, and evaluate the changes in the antibiotic within the matrix. The antibacterial properties of CLP and its combination with PRF were tested in a microdilution test against reference cultures and clinical isolates of Staphylococcus aureus (S. aureus) or Staphylococcus epidermidis (S. epidermidis). Fouriertransform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analysis was done to evaluate the changes in the PRF_CLP matrix. Release kinetics of CLP was defined with ultra-performance liquid chromatography (UPLC). According to FTIR data, the use of PRF as a carrier for CLP ensured the structural changes in the CLP toward a more active form of clindamycin. A significant decrease in minimal bactericidal concentration values (from 1000 µg/mL to 62 µg/mL) against reference cultures and clinical isolates of S. aureus and S. epidermidis was observed for the CLP and PRF samples if compared to pure CLP solution. In vitro cell viability tests showed that PRF and PRF with CLP have higher cell viability than 70% after 24 h and 48 h time points. This article indicates that CLP in combination with PRF showed higher antibacterial activity against S. aureus and S. epidermidis compared to pure CLP solution. This modified PRF could be used as a novel method to increase drug delivery and efficacy, and to reduce the risk of postoperative infection.publishersversionPeer reviewe

Development of vancomycin delivery systems based on autologous 3d platelet-rich fibrin matrices for bone tissue engineering

Funding Information: Funding: This research was funded by the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 857287 and the Latvian Council of Science research project No. lzp-2020/1-0054 “Development of antibacterial autologous fibrin matrices in maxillofacial surgery (MATRI-X)”. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Autologous platelet-rich fibrin (PRF) is derived from the blood and its use in the bone tissue engineering has emerged as an effective strategy for novel drug and growth factor delivery systems. Studies have approved that combined therapy with PRF ensures higher biological outcomes, but patients still undergo additional treatment with antibiotic drugs before, during, and even after the implantation of biomaterials with PRF. These systematically used drugs spread throughout the blood and lead not only to positive effects but may also induce adverse side effects on healthy tissues. Vancomycin hydrochloride (VANKA) is used to treat severe Staphylococcal infections but its absorption in the target tissue after oral administration is low; therefore, in this study, we have developed and analyzed two kinds of VANKA carriers—liposomes and microparticles in 3D PRF matrices. The adjustment, characterization, and analysis of VANKA carriers in 3D PRF scaffolds is carried out in terms of encapsulation efficiency, drug release kinetics and antibacterial activity; furthermore, we have studied the micro-and macrostructure of the scaffolds with microtomography.Peer reviewe

The essentials of marine biotechnology.

Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better health and well-being, new biomedicines, natural cosmeceuticals, environmental conservation, and sustainable energy sources. These societal needs stimulated the interest of researchers on the diverse and underexplored marine environments as promising and sustainable sources of biomolecules and biomass, and they are addressed by the emerging field of marine (blue) biotechnology. Blue biotechnology provides opportunities for a wide range of initiatives of commercial interest for the pharmaceutical, biomedical, cosmetic, nutraceutical, food, feed, agricultural, and related industries. This article synthesizes the essence, opportunities, responsibilities, and challenges encountered in marine biotechnology and outlines the attainment and valorization of directly derived or bio-inspired products from marine organisms. First, the concept of bioeconomy is introduced. Then, the diversity of marine bioresources including an overview of the most prominent marine organisms and their potential for biotechnological uses are described. This is followed by introducing methodologies for exploration of these resources and the main use case scenarios in energy, food and feed, agronomy, bioremediation and climate change, cosmeceuticals, bio-inspired materials, healthcare, and well-being sectors. The key aspects in the fields of legislation and funding are provided, with the emphasis on the importance of communication and stakeholder engagement at all levels of biotechnology development. Finally, vital overarching concepts, such as the quadruple helix and Responsible Research and Innovation principle are highlighted as important to follow within the marine biotechnology field. The authors of this review are collaborating under the European Commission-funded Cooperation in Science and Technology (COST) Action Ocean4Biotech – European transdisciplinary networking platform for marine biotechnology and focus the study on the European state of affairs

Delayed reactions to reusable protective gloves.

The materials in plastic protective gloves are thought to cause less contact allergy than rubber gloves. Our aim was to estimate the frequency of delayed reactions to different types of reusable protective gloves among dermatitis patients. 2 x 2 cm pieces of polyvinyl chloride (PVC) gloves, nitrile gloves, and natural rubber latex (NRL) gloves were tested as is in consecutive dermatitis patients tested with the baseline series. Among 658 patients, 6 patients reacted to PVC gloves and 6 patients to the NRL gloves. None reacted to both these types of gloves. Five of six patients with reactions to rubber gloves reacted to thiuram mix in the baseline series. Delayed reactions to reusable PVC gloves may be as common as to reusable NRL gloves. In contrast to most reactions to the NRL glove, the reactions to the PVC glove had no obvious association with reactions to any allergen(s) in the baseline series

Enzymatically Crosslinked In Situ Synthesized Silk/Gelatin/Calcium Phosphate Hydrogels for Drug Delivery

Our research focuses on combining the valuable properties of silk fibroin (SF) and calcium phosphate (CaP). SF is a natural protein with an easily modifiable structure; CaP is a mineral found in the human body. Most of the new age biocomposites lack interaction between organic/inorganic phase, thus SF/CaP composite could not only mimic the natural bone, but could also be used to make drug delivery systems as well, which can ensure both healing and regeneration. CaP was synthesized in situ in SF at different pH values, and then crosslinked with gelatin (G), horseradish peroxide (HRP), and hydrogen peroxide (H2O2). In addition, dexamethasone phosphate (DEX) was incorporated in the hydrogel and drug delivery kinetics was studied. Hydrogel made at pH 10.0 was found to have the highest gel fraction 110.24%, swelling degree 956.32%, and sustained drug delivery for 72 h. The highest cell viability was observed for the hydrogel, which contained brushite (pH 6)—512.43%