Delayed hemothorax following blunt thoracic trauma: a case report.

BACKGROUND: Late hemothorax is a rare complication of blunt chest trauma. The longest reported time interval between the traumatic event and the development of hemothorax is 44 days. CASE PRESENTATION: An elderly patient with right-sided rib fractures from chest trauma, managed initially with closed thoracostomy, presented with a delayed hemothorax that occurred 60 days after initial management, necessitating conservative and then surgical intervention due to the patient's frail condition and associated complications. CONCLUSIONS: This case emphasizes the clinical challenge and significance of delayed hemothorax in chest trauma, highlighting the need for vigilance and potential surgical correction in complex presentations, especially in the elderly.

Surgical stabilization of rib fractures under extracorporeal membrane oxygenation: A case report.

A 47-year-old male patient was referred to a level 1 trauma center with refractory acute respiratory distress syndrome, bilateral lung contusions, and flail chest after initial management for injuries sustained 5 days prior from an 8-m fall from a tower crane. Surgical stabilization of the rib fractures was achieved under extracorporeal membrane oxygenation support, with successful decannulation 4 days after surgery. The patient was discharged after 42 days and following multidisciplinary interventions. Use of extracorporeal membrane oxygenation support in blunt chest trauma patients presents a valuable opportunity as it may enable earlier surgical intervention and reduce in-hospital complications.

Additive Manufacturing of Nanocellulose Aerogels with Structure-Oriented Thermal, Mechanical, and Biological Properties.

Additive manufacturing (AM) is widely recognized as a versatile tool for achieving complex geometries and customized functionalities in designed materials. However, the challenge lies in selecting an appropriate AM method that simultaneously realizes desired microstructures and macroscopic geometrical designs in a single sample. This study presents a direct ink writing method for 3D printing intricate, high-fidelity macroscopic cellulose aerogel forms. The resulting aerogels exhibit tunable anisotropic mechanical and thermal characteristics by incorporating fibers of different length scales into the hydrogel inks. The alignment of nanofibers significantly enhances mechanical strength and thermal resistance, leading to higher thermal conductivities in the longitudinal direction (65 mW m-1 K-1) compared to the transverse direction (24 mW m-1 K-1). Moreover, the rehydration of printed cellulose aerogels for biomedical applications preserves their high surface area (≈300 m2 g-1) while significantly improving mechanical properties in the transverse direction. These printed cellulose aerogels demonstrate excellent cellular viability (>90% for NIH/3T3 fibroblasts) and exhibit robust antibacterial activity through in situ-grown silver nanoparticles.

Sustainable Silk-Based Particulate Systems for the Controlled Release of Pharmaceuticals and Bioactive Agents in Wound Healing and Skin Regeneration.

The increasing demand for innovative approaches in wound healing and skin regeneration has prompted extensive research into advanced biomaterials. This review focuses on showcasing the unique properties of sustainable silk-based particulate systems in promoting the controlled release of pharmaceuticals and bioactive agents in the context of wound healing and skin regeneration. Silk fibroin and sericin are derived from well-established silkworm production and constitute a unique biocompatible and biodegradable protein platform for the development of drug delivery systems. The controlled release of therapeutic compounds from silk-based particulate systems not only ensures optimal bioavailability but also addresses the challenges associated with conventional delivery methods. The multifaceted benefits of silk proteins, including their inherent biocompatibility, versatility, and sustainability, are explored in this review. Furthermore, the intricate mechanisms by which controlled drug release takes place from silk-based carriers are discussed.

Compendium of Safety Regulatory for Safe Applications of Aerogels.

An increasing number of aerogels as nanostructured highly porous materials are entering the market in every day products, with an attractive portfolio of properties for emerging applications ranging from health care and leisure to electronics, cosmetics, energy, agriculture, food and environmental. However, the novelty in properties and forms of aerogels makes the development of a legislative framework particularly challenging for ensuring the safe development and use of nano-enabled products. The presented safety regulatory Compendium intends to share knowledge with the international aerogels community, as well as end-users and stakeholders, on the regulatory and safe handling procedures, as best safety practices, to be followed during the production process, handling, transport and end-use of aerogel-based formulations to mitigate human and environmental risks considering lack of data availability for this purpose in general.

Expanding the Potential of Self-Assembled Silk Fibroin as Aerogel Particles for Tissue Regeneration.

A newly produced silk fibroin (SF) aerogel particulate system using a supercritical carbon dioxide (scCO2)-assisted drying technology is herein proposed for biomedical applications. Different concentrations of silk fibroin (3%, 5%, and 7% (w/v)) were explored to investigate the potential of this technology to produce size- and porosity-controlled particles. Laser diffraction, helium pycnometry, nitrogen adsorption-desorption analysis and Fourier Transform Infrared with Attenuated Total Reflectance (FTIR-ATR) spectroscopy were performed to characterize the physicochemical properties of the material. The enzymatic degradation profile of the SF aerogel particles was evaluated by immersion in protease XIV solution, and the biological properties by cell viability and cell proliferation assays. The obtained aerogel particles were mesoporous with high and concentration dependent specific surface area (203-326 m2/g). They displayed significant antioxidant activity and sustained degradation in the presence of protease XIV enzyme. The in vitro assessment using human dermal fibroblasts (HDF) confirm the particles' biocompatibility, as well as the enhancement in cell viability and proliferation.

Aerogels as Carriers for Oral Administration of Drugs: An Approach towards Colonic Delivery.

Polysaccharide aerogels have emerged as a highly promising technology in the field of oral drug delivery. These nanoporous, ultralight materials, derived from natural polysaccharides such as cellulose, starch, or chitin, have significant potential in colonic drug delivery due to their unique properties. The particular degradability of polysaccharide-based materials by the colonic microbiota makes them attractive to produce systems to load, protect, and release drugs in a controlled manner, with the capability to precisely target the colon. This would allow the local treatment of gastrointestinal pathologies such as colon cancer or inflammatory bowel diseases. Despite their great potential, these applications of polysaccharide aerogels have not been widely explored. This review aims to consolidate the available knowledge on the use of polysaccharides for oral drug delivery and their performance, the production methods for polysaccharide-based aerogels, the drug loading possibilities, and the capacity of these nanostructured systems to target colonic regions.

Intravitreal implants manufactured by supercritical foaming for treating retinal diseases.

Chronic retinal diseases, such as age-related macular degeneration (AMD), are a major cause of global visual impairment. However, current treatment methods involving repetitive intravitreal injections pose financial and health burdens for patients. The development of controlled drug release systems, particularly for biological drugs, is still an unmet need in prolonging drug release within the vitreous chamber. To address this, green supercritical carbon dioxide (scCO2) foaming technology was employed to manufacture porous poly(lactic-co-glycolic acid) (PLGA)-based intravitreal implants loaded with dexamethasone. The desired implant dimensions were achieved through 3D printing of customised moulds. By varying the depressurisation rates during the foaming process, implants with different porosities and dexamethasone release rates were successfully obtained. These implants demonstrated controlled drug release for up to four months, surpassing the performance of previously developed implants. In view of the positive results obtained, a pilot study was conducted using the monoclonal antibody bevacizumab to explore the feasibility of this technology for preparing intraocular implants loaded with biologic drug molecules. Overall, this study presents a greener and more sustainable alternative to conventional implant manufacturing techniques, particularly suited for drugs that are susceptible to degradation under harsh conditions.

Hollow Particles Obtained by Prilling and Supercritical Drying as a Potential Conformable Dressing for Chronic Wounds.

The production of aerogels for different applications has been widely known, but the use of polysaccharide-based aerogels for pharmaceutical applications, specifically as drug carriers for wound healing, is being recently explored. The main focus of this work is the production and characterization of drug-loaded aerogel capsules through prilling in tandem with supercritical extraction. In particular, drug-loaded particles were produced by a recently developed inverse gelation method through prilling in a coaxial configuration. Particles were loaded with ketoprofen lysinate, which was used as a model drug. The core-shell particles manufactured by prilling were subjected to a supercritical drying process with CO2 that led to capsules formed by a wide hollow cavity and a tunable thin aerogel layer (40 µm) made of alginate, which presented good textural properties in terms of porosity (89.9% and 95.3%) and a surface area up to 417.0 m2/g. Such properties allowed the hollow aerogel particles to absorb a high amount of wound fluid moving very quickly (less than 30 s) into a conformable hydrogel in the wound cavity, prolonging drug release (till 72 h) due to the in situ formed hydrogel that acted as a barrier to drug diffusion.

Green Processing of Neat Poly(lactic acid) Using Carbon Dioxide under Elevated Pressure for Preparation of Advanced Materials: A Review (2012-2022).

This review provides a concise overview of up-to-date developments in the processing of neat poly(lactic acid) (PLA), improvement in its properties, and preparation of advanced materials using a green medium (CO2 under elevated pressure). Pressurized CO2 in the dense and supercritical state is a superior alternative medium to organic solvents, as it is easily available, fully recyclable, has easily tunable properties, and can be completely removed from the final material without post-processing steps. This review summarizes the state of the art on PLA drying, impregnation, foaming, and particle generation by the employment of dense and supercritical CO2 for the development of new materials. An analysis of the effect of processing methods on the final material properties was focused on neat PLA and PLA with an addition of natural bioactive components. It was demonstrated that CO2-assisted processes enable the control of PLA properties, reduce operating times, and require less energy compared to conventional ones. The described environmentally friendly processing techniques and the versatility of PLA were employed for the preparation of foams, aerogels, scaffolds, microparticles, and nanoparticles, as well as bioactive materials. These PLA-based materials can find application in tissue engineering, drug delivery, active food packaging, compostable packaging, wastewater treatment, or thermal insulation, among others.

Synthesis of Highly Luminescent Silica-Coated Upconversion Nanoparticles from Lanthanide Oxides or Nitrates Using Co-Precipitation and Sol-Gel Methods.

Upconversion nanoparticles (UCNPs) are under consideration for their use as bioimaging probes with enhanced optical performance for real time follow-up under non-invasive conditions. Photostable and core-shell NaYF4:Yb3+, Er3+-SiO2 UCNPs obtained by a novel and simple co-precipitation method from lanthanide nitrates or oxides were herein synthesized for the first time. The sol-gel Stöber method followed by oven or supercritical gel drying was used to confer biocompatible surface properties to UCNPs by the formation of an ultrathin silica coating. Upconversion (UC) spectra were studied to evaluate the fluorescence of UCNPs upon red/near infrared (NIR) irradiation. ζ-potential measurements, TEM analyses, XRD patterns and long-term physicochemical stability were also assessed and confirmed that the UCNPs co-precipitation synthesis is a shape- and phase-controlling approach. The bio- and hemocompatibility of the UCNPs formulation with the highest fluorescence intensity was evaluated with murine fibroblasts and human blood, respectively, and provided excellent results that endorse the efficacy of the silica gel coating. The herein synthesized UCNPs can be regarded as efficient fluorescent probes for bioimaging purposes with the high luminescence, physicochemical stability and biocompatibility required for biomedical applications.

Biological Thermal Performance of Organic and Inorganic Aerogels as Patches for Photothermal Therapy.

Aerogels are materials with unique properties, among which are low density and thermal conductivity. They are also known for their exquisite biocompatibility and biodegradability. All these features make them attractive for biomedical applications, such as their potential use in photothermal therapy (PTT). This technique is, yet, still associated with undesirable effects on surrounding tissues which emphasizes the need to minimize the exposure of healthy regions. One way to do so relies on the use of materials able to block the radiation and the heat generated. Aerogels might be potentially useful for this purpose by acting as insulators. Silica- and pectin-based aerogels are reported as the best inorganic and organic thermal insulators, respectively; thus, the aim of this work relies on assessing the possibility of using these materials as light and thermal insulators and delimiters for PTT. Silica- and pectin-based aerogels were prepared and fully characterized. The thermal protection efficacy of the aerogels when irradiated with a near-infrared laser was assessed using phantoms and ex vivo grafts. Lastly, safety was assessed in human volunteers. Both types presented good textural properties and safe profiles. Moreover, thermal activation unveils the better performance of silica-based aerogels, confirming the potential of this material for PTT.

Preparation of Vancomycin-Loaded Aerogels Implementing Inkjet Printing and Superhydrophobic Surfaces.

Chronic wounds are physical traumas that significantly impair the quality of life of over 40 million patients worldwide. Aerogels are nanostructured dry porous materials that can act as carriers for the local delivery of bioactive compounds at the wound site. However, aerogels are usually obtained with low drug loading yields and poor particle size reproducibility and urges the implementation of novel and high-performance processing strategies. In this work, alginate aerogel particles loaded with vancomycin, an antibiotic used for the treatment of Staphylococcus aureus infections, were obtained through aerogel technology combined with gel inkjet printing and water-repellent surfaces. Alginate aerogel particles showed high porosity, large surface area, a well-defined spherical shape and a reproducible size (609 ± 37 µm). Aerogel formulation with vancomycin loadings of up to 33.01 ± 0.47 µg drug/mg of particle were obtained with sustained-release profiles from alginate aerogels for more than 7 days (PBS pH 7.4 medium). Overall, this novel green aerogel processing strategy allowed us to obtain nanostructured drug delivery systems with improved drug loading yields that can enhance the current antibacterial treatments for chronic wounds.

Treatment of early rheumatoid arthritis: Methotrexate and beyond.

For the last several decades, the standard of care for the initial management of rheumatoid arthritis (RA) has been methotrexate. Methotrexate is effective as monotherapy and in combination with conventional, biologic, and targeted-synthetic therapies. Methotrexate is generally well-tolerated, but has important, albeit uncommon, potential side-effects including a risk of liver toxicity and cytopenias. Some studies suggest that more active monitoring in patients with fatty liver disease may be appropriate. With reassuring safety data, more rapid dose escalation and use of subcutaneous therapy may provide even greater success. Some off-target benefits such as a reduction in cardiovascular disease risk have also been demonstrated, though these studies may suffer from confounding. Recent published guidelines continue to endorse methotrexate as first-line therapy. Methotrexate is a low-cost, safe, and effective therapy for RA that should not be overlooked nor too quickly abandoned.

3D-Printed, Dual Crosslinked and Sterile Aerogel Scaffolds for Bone Tissue Engineering.

The fabrication of bioactive three-dimensional (3D) hydrogel scaffolds from biocompatible materials with a complex inner structure (mesoporous and macroporous) and highly interconnected porosity is crucial for bone tissue engineering (BTE). 3D-printing technology combined with aerogel processing allows the fabrication of functional nanostructured scaffolds from polysaccharides for BTE with personalized geometry, porosity and composition. However, these aerogels are usually fragile, with fast biodegradation rates in biological aqueous fluids, and they lack the sterility required for clinical practice. In this work, reinforced alginate-hydroxyapatite (HA) aerogel scaffolds for BTE applications were obtained by a dual strategy that combines extrusion-based 3D-printing and supercritical CO2 gel drying with an extra crosslinking step. Gel ageing in CaCl2 solutions and glutaraldehyde (GA) chemical crosslinking of aerogels were performed as intermediate and post-processing reinforcement strategies to achieve highly crosslinked aerogel scaffolds. Nitrogen adsorption-desorption (BET) and SEM analyses were performed to assess the textural parameters of the resulting alginate-HA aerogel scaffolds. The biological evaluation of the aerogel scaffolds was performed regarding cell viability, hemolytic activity and bioactivity for BTE. The impact of scCO2-based post-sterilization treatment on scaffold properties was also assessed. The obtained aerogels were dual porous, bio- and hemocompatible, as well as endowed with high bioactivity that is dependent on the HA content. This work is a step forward towards the optimization of the physicochemical performance of advanced biomaterials and their sterilization.

Supercritical CO2 sterilization: An effective treatment to reprocess FFP3 face masks and to reduce waste during COVID-19 pandemic.

The outbreak of COVID-19 pandemic unveiled an unprecedented scarcity of personal protective equipment (PPE) available in sanitary premises and for the population worldwide. This situation fostered the development of new strategies to reuse PPE that would ensure sterility and, simultaneously, preserve the filtering properties of the materials. In addition, the reuse of PPEs by reprocessing could reduce the environmental impact of the massive single-use and disposal of these materials. Conventional sterilization techniques such as steam or dry heat, ethylene oxide, and gamma irradiation may alter the functional properties of the PPEs and/or leave toxic residues. Supercritical CO2 (scCO2)-based sterilization is herein proposed as a safe, sustainable, and rapid sterilization method for contaminated face masks while preserving their performance. The functional (bacterial filtration efficiency, breathability, splash resistance, straps elasticity) properties of the processed FFP3 face masks were evaluated after 1 and 10 cycles of sterilization. Log-6 sterilization reduction levels were obtained for face masks contaminated with Bacillus pumilus endospores at mild operating conditions (CO2 at 39 °C and 100 bar for 30 min) and with low contents of H2O2 (150 ppm). Physicochemical properties of the FFP3 face masks remained unchanged after reprocessing and differences in efficacy were not observed neither in the filtration tests, following UNE-EN 14683, nor in the integrity of FFP3 filtration after the sterilization process. The herein presented method based on scCO2 technology is the first reported protocol achieving the reprocessing of FFP3 masks up to 10 cycles while preserving their functional properties.

Combined sterilization and fabrication of drug-loaded scaffolds using supercritical CO2 technology.

The access of biodegradable scaffolds to the clinical arena is constrained by the absence of a suitable sterilization technique for the processing of advanced polymeric materials. Sterilization with supercritical CO2 (scCO2) may circumvent some technological limitations (e.g., low temperature, no chemical residues on the material), although scCO2 can plasticize the polymer depending on the processing conditions used. In this latter case, the integration of the manufacturing and sterilization processes is of particular interest to obtain sterile and customized scaffolds in a single step. In this work, scCO2 was exploited as a concomitantly foaming and sterilizing agent for the first time, developing a one-step process for the production of vancomycin-loaded poly(ε-caprolactone) (PCL) bone scaffolds. The effect of the CO2 contact time on the sterility levels of the procedure was investigated, and the sterilization efficiency was evaluated against dry spores (Bacillus stearothermophilus, Bacillus pumilus and Bacillus atrophaeus). Vancomycin-loaded PCL scaffolds had relevant sustained release profiles for the prophylaxis of infections at the grafted area, even those caused by methicillin-resistant Staphylococcus aureus (MRSA). The biological performance of the scaffolds was evaluated in vitro regarding human mesenchymal stem cells (hMSCs) attachment and growth. Finally, the biocompatibility and angiogenic response of the manufactured sterile scaffolds was assessed in ovo through chick chorioallantoic membrane (CAM) assays.

3D-printed alginate-hydroxyapatite aerogel scaffolds for bone tissue engineering.

3D-printing technology allows the automated and reproducible manufacturing of functional structures for tissue engineering with customized geometries and compositions by depositing materials layer-by-layer with high precision. For these purposes, the production of bioactive gel-based 3D-scaffolds made of biocompatible materials with well-defined internal structure comprising a dual (mesoporous and macroporous) and highly interconnected porosity is essential. In this work, aerogel scaffolds for bone regeneration purposes were obtained by an innovative strategy that combines the 3D-printing of alginate-hydroxyapatite (HA) hydrogels and the supercritical CO2 drying of the gels. BET and SEM analyses were performed to assess the textural parameters of the obtained aerogel scaffolds and the dimensional accuracy to the original computer-aided design (CAD) design was also evaluated. The biological characterization of the aerogel scaffolds was also carried out regarding cell viability, adhesion and migration capacity. The obtained alginate-HA aerogel scaffolds were highly porous, biocompatible, with high fidelity to the CAD-pattern and also allowed the attachment and proliferation of mesenchymal stem cells (MSCs). An enhancement of the fibroblast migration toward the damaged area was observed in the presence of the aerogel formulations tested, which is positive in terms of bone regeneration.

Prehospital paramedic pleural decompression: A systematic review.

BACKGROUND: Tension pneumothorax (TPT) is a frequent life-threat following thoracic injury. Time-critical decompression of the pleural cavity improves survival. However, whilst paramedics utilise needle thoracostomy (NT) and/or finger thoracostomy (FT) in the prehospital setting, the superiority of one technique over the other remains unknown. AIM: To determine and compare procedural success, complications and mortality between NT and FT for treatment of a suspected TPT when performed by paramedics. METHODS: We searched four databases (Ovid Medline, PubMed, CINAHL and Embase) from their commencement until 25th August 2020. Studies were included if they analysed patients suffering from a suspected TPT who were treated in the prehospital setting with a NT or FT by paramedics (or local equivalent nonphysicians). RESULTS: The search yielded 293 articles after duplicates were removed of which 19 were included for final analysis. Seventeen studies were retrospective (8 cohort; 7 case series; 2 case control) and two were prospective cohort studies. Only one study was comparative, and none were randomised controlled trials. Most studies were conducted in the USA (n=13) and the remaining in Australia (n=4), Switzerland (n=1) and Canada (n=1). Mortality ranged from 12.5% to 79% for NT and 64.7% to 92.9% for FT patients. A higher proportion of complications were reported among patients managed with NT (13.7%) compared to FT (4.8%). We extracted three common themes from the papers of what constituted as a successful pleural decompression; vital signs improvement, successful pleural cavity access and absence of TPT at hospital arrival. CONCLUSION: Evidence surrounding prehospital pleural decompression of a TPT by paramedics is limited. Available literature suggests that both FT and NT are safe for pleural decompression, however both procedures have associated complications. Additional high-quality evidence and comparative studies investigating the outcomes of interest is necessary to determine if and which procedure is superior in the prehospital setting.

Bioaerogels: Promising Nanostructured Materials in Fluid Management, Healing and Regeneration of Wounds.

Wounds affect one's quality of life and should be managed on a patient-specific approach, based on the particular healing phase and wound condition. During wound healing, exudate is produced as a natural response towards healing. However, excessive production can be detrimental, representing a challenge for wound management. The design and development of new healing devices and therapeutics with improved performance is a constant demand from the healthcare services. Aerogels can combine high porosity and low density with the adequate fluid interaction and drug loading capacity, to establish hemostasis and promote the healing and regeneration of exudative and chronic wounds. Bio-based aerogels, i.e., those produced from natural polymers, are particularly attractive since they encompass their intrinsic chemical properties and the physical features of their nanostructure. In this work, the emerging research on aerogels for wound treatment is reviewed for the first time. The current scenario and the opportunities provided by aerogels in the form of films, membranes and particles are identified to face current unmet demands in fluid managing and wound healing and regeneration.