RESUMO
A long-standing challenge is how to formulate proteins and vaccines to retain function during storage and transport and to remove the burdens of cold-chain management. Any solution must be practical to use, with the protein being released or applied using clinically relevant triggers. Advanced biologic therapies are distributed cold, using substantial energy, limiting equitable distribution in low-resource countries and placing responsibility on the user for correct storage and handling. Cold-chain management is the best solution at present for protein transport but requires substantial infrastructure and energy. For example, in research laboratories, a single freezer at -80 °C consumes as much energy per day as a small household1. Of biological (protein or cell) therapies and all vaccines, 75% require cold-chain management; the cost of cold-chain management in clinical trials has increased by about 20% since 2015, reflecting this complexity. Bespoke formulations and excipients are now required, with trehalose2, sucrose or polymers3 widely used, which stabilize proteins by replacing surface water molecules and thereby make denaturation thermodynamically less likely; this has enabled both freeze-dried proteins and frozen proteins. For example, the human papilloma virus vaccine requires aluminium salt adjuvants to function, but these render it unstable against freeze-thaw4, leading to a very complex and expensive supply chain. Other ideas involve ensilication5 and chemical modification of proteins6. In short, protein stabilization is a challenge with no universal solution7,8. Here we designed a stiff hydrogel that stabilizes proteins against thermal denaturation even at 50 °C, and that can, unlike present technologies, deliver pure, excipient-free protein by mechanically releasing it from a syringe. Macromolecules can be loaded at up to 10 wt% without affecting the mechanism of release. This unique stabilization and excipient-free release synergy offers a practical, scalable and versatile solution to enable the low-cost, cold-chain-free and equitable delivery of therapies worldwide.
Assuntos
Armazenamento de Medicamentos , Hidrogéis , Desnaturação Proteica , Estabilidade Proteica , Proteínas , Seringas , Humanos , Excipientes , Liofilização , Hidrogéis/química , Proteínas/administração & dosagem , Proteínas/química , Proteínas/economia , Trealose , Congelamento , Refrigeração , Vacinas contra Papillomavirus/química , Armazenamento de Medicamentos/economia , Armazenamento de Medicamentos/métodosRESUMO
Lymph nodes are crucial organs of the adaptive immune system, orchestrating T cell priming, activation and tolerance. T cell activity and function are highly regulated by lymph nodes, which have a unique structure harbouring distinct cells that work together to detect and respond to pathogen-derived antigens. Here we show that implanted patient-derived freeze-dried lymph nodes loaded with chimeric antigen receptor T cells improve delivery to solid tumours and inhibit tumour recurrence after surgery. Chimeric antigen receptor T cells can be effectively loaded into lyophilized lymph nodes, whose unaltered meshwork and cytokine and chemokine contents promote chimeric antigen receptor T cell viability and activation. In mouse models of cell-line-derived human cervical cancer and patient-derived pancreatic cancer, delivery of chimeric antigen receptor T cells targeting mesothelin via the freeze-dried lymph nodes is more effective in preventing tumour recurrence when compared to hydrogels containing T-cell-supporting cytokines. This tissue-mediated cell delivery strategy holds promise for controlled release of various cells and therapeutics with long-term activity and augmented function.
Assuntos
Liofilização , Linfonodos , Mesotelina , Receptores de Antígenos Quiméricos , Animais , Humanos , Camundongos , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/metabolismo , Linfonodos/imunologia , Linfócitos T/imunologia , Linfócitos T/citologia , Linhagem Celular Tumoral , Feminino , Proteínas Ligadas por GPI/imunologia , Proteínas Ligadas por GPI/metabolismo , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologiaAssuntos
Cromossomos de Mamíferos , Fósseis , Liofilização , Mamutes , Pele , Animais , Cromossomos de Mamíferos/genética , Mamutes/genética , Pele/citologia , Pele/metabolismoRESUMO
Direct imaging of semi-solid lipids, such as myelin, is of great interest as a noninvasive biomarker of neurodegenerative diseases. Yet, the short T2 relaxation times of semi-solid lipid protons hamper direct detection through conventional magnetic resonance imaging (MRI) pulse sequences. In this study, we examined whether a three-dimensional ultrashort echo time (3D UTE) sequence can directly acquire signals from membrane lipids. Membrane lipids from red blood cells (RBC) were collected from commercially available blood as a general model of the myelin lipid bilayer and subjected to D2O exchange and freeze-drying for complete water removal. Sufficiently high MR signals were detected with the 3D UTE sequence, which showed an ultrashort T2* of â¼77-271 µs and a short T1 of â¼189 ms for semi-solid RBC membrane lipids. These measurements can guide designing UTE-based sequences for direct in vivo imaging of membrane lipids.
Assuntos
Membrana Eritrocítica , Imageamento por Ressonância Magnética , Lipídeos de Membrana , Bainha de Mielina , Humanos , Imageamento por Ressonância Magnética/métodos , Bainha de Mielina/química , Membrana Eritrocítica/química , Membrana Eritrocítica/metabolismo , Lipídeos de Membrana/química , Liofilização , Eritrócitos/metabolismoRESUMO
We evaluated the in vitro effects of lyophilization for 2 vesicular stomatitis virus-based vaccines by using 3 stabilizing formulations and demonstrated protective immunity of lyophilized/reconstituted vaccine in guinea pigs. Lyophilization increased stability of the vaccines, but specific vesicular stomatitis virus-based vaccines will each require extensive analysis to optimize stabilizing formulations.
Assuntos
Modelos Animais de Doenças , Liofilização , Estomatite Vesicular , Vacinas Virais , Animais , Cobaias , Vacinas Virais/imunologia , Vacinas Virais/administração & dosagem , Estomatite Vesicular/imunologia , Estomatite Vesicular/prevenção & controle , Estomatite Vesicular/virologia , Vesiculovirus/imunologia , Vesiculovirus/genética , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Eficácia de Vacinas , Vírus da Estomatite Vesicular Indiana/imunologiaRESUMO
The healthcare burden imposed by bacterial infections demands robust and accessible diagnostic methods that can be performed outside hospitals and centralized laboratories. Here, we report Pathogen Assay with Ratiometric Luminescence (PEARL), a sensitive and easy-to-operate platform for detecting pathogenic bacteria. The PEARL leveraged a color-changeable CRISPR-Cas12a sensor and recombinase polymerase amplification to elicit ratiometric bioluminescence responses to target inputs. This platform enabled robust and visualized identification of attomolar bacteria genome deoxyribonucleic acid according to the color changes of the reactions. In addition, the components of the color-changeable Cas12a sensor could be lyophilized for 3 month storage at ambient temperature and then be fully activated with the amplicons derived from crude bacterial lysates, reducing the requirements for cold-chain storage and tedious handling steps. We demonstrated that the PEARL assay is applicable for identifying the infections caused by Pseudomonas aeruginosa in different clinical specimens, including sputa, urines, and swabs derived from wounds. These results revealed the potential of PEARL to be used by untrained personnel, which will facilitate decentralized pathogen diagnosis in community- and resource-limited regions.
Assuntos
Sistemas CRISPR-Cas , Medições Luminescentes , Pseudomonas aeruginosa , Sistemas CRISPR-Cas/genética , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/genética , Humanos , Liofilização , Cor , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Técnicas Biossensoriais , Proteínas Associadas a CRISPR/metabolismo , LuminescênciaRESUMO
The oral administration of protein therapeutics in solid dosage form is gaining popularity due to its benefits, such as improved medication adherence, convenience, and ease of use for patients compared to traditional parental delivery. However, formulating oral biologics presents challenges related to pH barriers, enzymatic breakdown, and poor bioavailability. Therefore, understanding the interaction between excipients and protein therapeutics in the solid state is crucial for formulation development. In this Letter, we present a case study focused on investigating the role of excipients in protein aggregation during the production of a solid dosage form of a single variable domain on a heavy chain (VHH) protein. We employed solid-state hydrogen-deuterium exchange coupled with mass spectrometry (ssHDX-MS) at both intact protein and peptide levels to assess differences in protein-excipient interactions between two formulations. ssHDX-MS analysis revealed that one formulation effectively prevents protein aggregation during compaction by blocking ß-sheets across the VHH protein, thereby preventing ß-sheet-ß-sheet interactions. Spatial aggregation propensity (SAP) mapping and cosolvent simulation from molecular dynamics (MD) simulation further validated the protein-excipient interaction sites identified through ssHDX-MS. Additionally, the MD simulation demonstrated that the interaction between the VHH protein and excipients involves hydrophilic interactions and/or hydrogen bonding. This novel approach holds significant potential for understanding protein-excipient interactions in the solid state and can guide the formulation and process development of orally delivered protein dosage forms, ultimately enhancing their efficacy and stability.
Assuntos
Medição da Troca de Deutério , Excipientes , Humanos , Deutério/química , Excipientes/química , Medição da Troca de Deutério/métodos , Simulação de Dinâmica Molecular , Agregados Proteicos , Liofilização/métodos , Proteínas/química , Hidrogênio/química , Espectrometria de Massas/métodosRESUMO
Currently, phage biocontrol is increasingly used as a green and natural technology for treating Salmonella and other infections, but phages exhibit instability and activity loss during storage. Therefore, in this study, the effects of lyophilization on the activity and stability of phage cocktails for the control of multidrug-resistant Salmonella in broiler chickens were determined. Eight serotypes of Salmonella were isolated and identified from broiler chicken farms, and bacteriophages against multidrug-resistant Salmonella enterica subsp. enterica serovar Kentucky, Salmonella enterica subsp. enterica serovar Typhimrium and Salmonella enterica subsp. enterica serovar Enteritidis were isolated. The bacteriophage cocktail was prepared and lyophilized, and it was subjected to in vitro and in vivo examinations. A reconstituted lyophilized bacteriophage cocktail was used for the oral treatment of chicks before and after challenge with multidrug-resistant S. Kentucky. The colonization of cecum by S. Kentucky was detected by using real-time PCR, and the serum levels of IgM, IgA and IL-4 and pathological changes in the different groups were detected. Three Caudovirales phages families were identified including Autographiviridae, Straboviridae and Drexlerviridae against multidrug-resistant S. Kentucky, S. Typhimrium and S. Enteritidis. The groups treated with the bacteriophage cocktail showed no clinical signs, no postmortem lesions, and a mortality rate of 0%, which improved the growth performance parameters. Additionally, the estimated serum levels of IgM, IgA and IL-4 were significantly greater in the bacteriophage cocktail-treated groups. Lyophilization effectively preserves the long-term storage stability of phages. Therefore, lyophilized bacteriophage cocktail therapy is a valuable approach for controlling multidrug-resistant Salmonella infections in broiler chickens.
Assuntos
Galinhas , Farmacorresistência Bacteriana Múltipla , Liofilização , Doenças das Aves Domésticas , Salmonelose Animal , Fagos de Salmonella , Salmonella , Animais , Galinhas/microbiologia , Liofilização/métodos , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/terapia , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/prevenção & controle , Salmonelose Animal/microbiologia , Salmonelose Animal/terapia , Salmonella/virologia , Fagos de Salmonella/fisiologia , Ceco/microbiologia , Ceco/virologia , Terapia por Fagos/métodos , Bacteriófagos/genética , Bacteriófagos/fisiologia , Bacteriófagos/isolamento & purificaçãoRESUMO
BACKGROUND: Hemorrhagic shock is well documented as a leading cause of preventable fatalities among military casualties. During military operations plasma can be transfused while waiting for whole blood. This study was conducted to assess the safety and efficacy of two new freeze-dried plasma formulations in a porcine model of traumatic hemorrhagic shock. STUDY DESIGN AND METHODS: In the face of species-specific transfusion, transfusible blood products were derived from porcine sources. The efficacy of three lyophilized plasma (LP) formulations was evaluated: lyophilized plasma (LP), concentrated lyophilized plasma (CLP), and platelet-rich concentrated lyophilized plasma (PCLP). Pigs were subjected to multi-trauma and hemorrhagic shock. Ninety minutes post-shock induction, the animals were treated with one of the three lyophilized products. Monitoring included systolic blood pressure and cardiac output. Point-of-care and laboratory diagnostic tests were used to assess renal function, real-time hemostasis (ROTEM), and coagulation. Histological examinations of kidney, lung, and muscle tissues were conducted 4 h after shock induction. RESULTS: CLP and PCLP significantly improved systolic blood pressure and cardiac output and positively influenced base excess, creatinine, various ROTEM, and coagulation markers compared with standard LP without histologic modification. No adverse effect was associated with the transfusion of any of the plasma products throughout the experimental procedures. CONCLUSION: Both CLP and PCLP exhibit promising therapeutic potential for managing hemorrhagic shock in scenario where whole blood supplies are limited. However, the distinct physiological and coagulation characteristics of the swine model necessitate further investigation using humanized preclinical models to fully understand their clinical applicability and constraints.
Assuntos
Liofilização , Plasma , Choque Hemorrágico , Animais , Suínos , Choque Hemorrágico/terapia , Modelos Animais de Doenças , Transfusão de Componentes SanguíneosRESUMO
BACKGROUND: Blood products form the cornerstone of contemporary hemorrhage control but are limited resources. Freeze-dried plasma (FDP), which contains coagulation factors, is a promising adjunct in hemostatic resuscitation. We explore the association between FDP alone or in combination with other blood products on 24-h mortality. STUDY DESIGN AND METHODS: This is a secondary data analysis from a cross-sectional prospective observational multicenter study of adult trauma patients in the Western Cape of South Africa. We compare mortality among trauma patients at risk of hemorrhage in three treatment groups: Blood Products only, FDP + Blood Products, and FDP only. We apply inverse probability of treatment weighting and fit a multivariable Cox proportional hazards model to assess the hazard of 24-h mortality. RESULTS: Four hundred and forty-eight patients were included, and 55 (12.2%) died within 24 h of hospital arrival. Compared to the Blood Products only group, we found no difference in 24-h mortality for the FDP + Blood Product group (p = .40) and a lower hazard of death for the FDP only group (hazard = 0.38; 95% CI, 0.15-1.00; p = .05). However, sensitivity analyses showed no difference in 24-h mortality across treatments in subgroups with moderate and severe shock, early blood product administration, and accounting for immortal time bias. CONCLUSION: We found insufficient evidence to conclude there is a difference in relative 24-h mortality among trauma patients at risk for hemorrhage who received FDP alone, blood products alone, or blood products with FDP. There may be an adjunctive role for FDP in hemorrhagic shock resuscitation in settings with significantly restricted access to blood products.
Assuntos
Liofilização , Hemorragia , Plasma , Ferimentos e Lesões , Humanos , Feminino , Masculino , Hemorragia/mortalidade , Hemorragia/terapia , Hemorragia/etiologia , Adulto , Ferimentos e Lesões/mortalidade , Ferimentos e Lesões/terapia , Ferimentos e Lesões/complicações , Ferimentos e Lesões/sangue , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Transversais , África do Sul/epidemiologia , Transfusão de Componentes Sanguíneos , Ressuscitação/métodosRESUMO
In the clinical application of freeze-dried highly concentrated omalizumab formulations, extensive visible bubbles (VBs) can be generated and remain for a long period of time in the reconstitution process, which greatly reduces the clinical use efficiency. It is necessary to understand the forming and breaking mechanism of VBs in the reconstitution process, which is a key factor for efficient and safe administration of biopharmaceutical injection. The effects of different thermal treatments on the volume of VBs and stability of omalizumab, mAb-1, and mAb-2 were investigated. The internal microvoids of the cake were characterized by scanning electron microscopy and mercury intrusion porosimetry. Electron paramagnetic resonance was applied to obtain the molecular mobility of the protein during annealing. A large number of VBs were generated in the reconstitution process of unannealed omalizumab and remained for a long period of time. When annealing steps were added, the volume of VBs was dramatically reduced. When annealed at an aggressive temperature (i.e., -6 °C), although the volume of VBs decreased, the aggregation and acidic species increased significantly. Thus, our observations highlight the importance of setting an additional annealing step with a suitable temperature, which contributes to reducing the VBs while maintaining the stability of the high concentration freeze-dried protein formulation.
Assuntos
Omalizumab , Proteínas , Temperatura , Liofilização , Estabilidade de MedicamentosRESUMO
Vaccines have historically faced challenges regarding stability, especially in regions lacking a robust cold chain infrastructure. This review delves into established and emergent techniques to improve the thermostability of vaccines. We discuss the widely practiced lyophilization method, effectively transforming liquid vaccine formulations into a solid powdered state, enhancing storage and transportation ability. However, potential protein denaturation during lyophilization necessitates alternative stabilization methods. Cryoprotectants, namely, starch and sugar molecules, have shown promise in protecting vaccine antigens and adjuvants from denaturation and augmenting the stability of biologics during freeze-drying. Biomineralization, a less studied yet innovative approach, utilizes inorganic or organic-inorganic hybrids to encapsulate biological components of vaccines with a particular emphasis on metal-organic coordination polymers. Encapsulation in organic matrices to form particles or microneedles have also been studied in the context of vaccine thermostability, showing some ability to store outside the cold-chain. Unfortunately, few of these techniques have advanced to clinical trials that evaluate differences in storage conditions. Nonetheless, early trials suggest that alternative storage techniques are viable and emphasize the need for more comprehensive studies. This review underscores the pressing need for heat-stable vaccines, especially in light of the increasing global distribution challenges. Combining traditional methods with novel approaches holds promise for the future adaptability of vaccine distribution and use.
Assuntos
Temperatura Alta , Vacinas , Humanos , Estabilidade de Medicamentos , Composição de Medicamentos/métodos , Vacinação , Liofilização/métodosRESUMO
Drying protein-based drugs, usually via lyophilization, can facilitate storage at ambient temperature and improve accessibility but many proteins cannot withstand drying and must be formulated with protective additives called excipients. However, mechanisms of protection are poorly understood, precluding rational formulation design. To better understand dry proteins and their protection, we examine Escherichia coli adenylate kinase (AdK) lyophilized alone and with the additives trehalose, maltose, bovine serum albumin, cytosolic abundant heat soluble protein D, histidine, and arginine. We apply liquid-observed vapor exchange NMR to interrogate the residue-level structure in the presence and absence of additives. We pair these observations with differential scanning calorimetry data of lyophilized samples and AdK activity assays with and without heating. We show that the amino acids do not preserve the native structure as well as sugars or proteins and that after heating the most stable additives protect activity best.
Assuntos
Adenilato Quinase , Escherichia coli , Liofilização , Trealose , Liofilização/métodos , Adenilato Quinase/metabolismo , Trealose/química , Soroalbumina Bovina/química , Excipientes/química , Varredura Diferencial de Calorimetria , Maltose/química , Histidina/química , Arginina/química , Espectroscopia de Ressonância MagnéticaRESUMO
Stabilization of proteins by disaccharides in lyophilized formulations depends on the interactions between the protein and the disaccharide (system homogeneity) and the sufficiently low mobility of the system. Human serum albumin (HSA) was lyophilized with disaccharides (sucrose and/or trehalose) in different relative concentrations. Solid-state nuclear magnetic resonance (ssNMR) spectroscopy 1H T1 and 1H T1ρ relaxation times were measured to determine the homogeneity of the lyophilized systems on 20-50 and 1-3 nm domains, respectively, with 1H T1 relaxation times also being used to determine the ß-relaxation rate. HSA/sucrose systems had longer 1H T1 relaxation times and were slightly more stable than HSA/trehalose systems in almost all cases shown. HSA/sucrose/trehalose systems have 1H T1 relaxation times between the HSA/sucrose and HSA/trehalose systems and did not result in a more stable system compared with binary systems. Inhomogeneity was evident in a sample containing relative concentrations of 10% HSA and 90% trehalose, suggesting trehalose crystallization during lyophilization. Under these stability conditions and with these ssNMR acquisition parameters, a 1H T1 relaxation time below 1.5 s correlated with an unstable sample, regardless of the disaccharide(s) used.
Assuntos
Liofilização , Espectroscopia de Ressonância Magnética , Sacarose , Trealose , Trealose/química , Sacarose/química , Liofilização/métodos , Humanos , Espectroscopia de Ressonância Magnética/métodos , Albumina Sérica Humana/química , Albumina Sérica/química , Estabilidade de Medicamentos , Química Farmacêutica/métodos , Excipientes/química , Dissacarídeos/químicaRESUMO
Poloxamer 188 (P188) was hypothesized to be a dual functional excipient, (i) a stabilizer in frozen solution to prevent ice-surface-induced protein destabilization and (ii) a bulking agent to provide elegant lyophiles. Based on X-ray diffractometry and differential scanning calorimetry, sucrose, in a concentration-dependent manner, inhibited P188 crystallization during freeze-drying, while trehalose had no such effect. The recovery of lactate dehydrogenase (LDH), the model protein, was evaluated after reconstitution. While low LDH recovery (â¼60%) was observed in the lyophiles prepared with P188, the addition of sugar improved the activity recovery to >85%. The secondary structure of LDH in the freeze-dried samples was assessed using infrared spectroscopy, and only moderate structural changes were observed in the lyophiles formulated with P188 and sugar. Thus, P188 can be a promising dual functional excipient in freeze-dried protein formulations. However, P188 alone does not function as a lyoprotectant and needs to be used in combination with a sugar.
Assuntos
Varredura Diferencial de Calorimetria , Excipientes , Liofilização , Poloxâmero , Trealose , Liofilização/métodos , Poloxâmero/química , Excipientes/química , Trealose/química , Varredura Diferencial de Calorimetria/métodos , Sacarose/química , Difração de Raios X , L-Lactato Desidrogenase/metabolismo , L-Lactato Desidrogenase/química , Cristalização/métodos , Química Farmacêutica/métodos , Proteínas/química , Composição de Medicamentos/métodos , CongelamentoRESUMO
Sucrose and trehalose pharmaceutical excipients are employed to stabilize protein therapeutics in a dried state. The mechanism of therapeutic protein stabilization is dependent on the sugars being present in an amorphous solid-state. Colyophilization of sugars with high glass transition polymers, polyvinylpyrrolidone (PVP), and poly(vinylpyrrolidone vinyl acetate) (PVPVA), enhances amorphous sugar stability. This study investigates the stability of colyophilized sugar-polymer systems in the frozen solution state, dried state postlyophilization, and upon exposure to elevated humidity. Binary systems of sucrose or trehalose with PVP or PVPVA were lyophilized with sugar/polymer ratios ranging from 2:8 to 8:2. Frozen sugar-PVPVA solutions exhibited a higher glass transition temperature of the maximally freeze-concentrated amorphous phase (Tg') compared to sugar-PVP solutions, despite the glass transition temperature (Tg) of PVPVA being lower than PVP. Tg values of all colyophilized systems were in a similar temperature range irrespective of polymer type. Greater hydrogen bonding between sugars and PVP and the lower hygroscopicity of PVPVA influenced polymer antiplasticization effects and the plasticization effects of residual water. Plasticization due to water sorption was investigated in a dynamic vapor sorption humidity ramping experiment. Lyophilized sucrose systems exhibited increased amorphous stability compared to trehalose upon exposure to the humidity. Recrystallization of trehalose was observed and stabilized by polymer addition. Lower concentrations of PVP inhibited trehalose recrystallization compared to PVPVA. These stabilizing effects were attributed to the increased hydrogen bonding between trehalose and PVP compared to trehalose and PVPVA. Overall, the study demonstrated how differences in polymer hygroscopicity and hydrogen bonding with sugars influence the stability of colyophilized amorphous dispersions. These insights into excipient solid-state stability are relevant to the development of stabilized biopharmaceutical solid-state formulations.
Assuntos
Estabilidade de Medicamentos , Excipientes , Liofilização , Polímeros , Povidona , Temperatura de Transição , Trealose , Liofilização/métodos , Povidona/química , Trealose/química , Excipientes/química , Polímeros/química , Sacarose/química , Açúcares/química , Ligação de Hidrogênio , Armazenamento de Medicamentos , Química Farmacêutica/métodos , Varredura Diferencial de Calorimetria , Umidade , Pirrolidinas/química , Compostos de Vinila/químicaRESUMO
Lanthanide-containing luminescent hydrogels have shown potential for sensing and imaging applications. Nonetheless, integrating lanthanide ions or complexes into the polymer matrix often results in the poor stability and mechanical strength of the hydrogels. This work presents an innovative approach to fabricating luminescent hydrogels with three dynamic cross-links: imine bond, boronate ester bond, and metal-ligand coordination. Europium(III) (Eu3+) ions are incorporated into a dual-cross-linked matrix composed of phenylboronic acid-polyethylenimine-modified gelatin (PPG) and alginate dialdehyde (ADA) through a combined treatment involving freeze-drying-swelling (FDS) and freeze-thawing (FT) processes. The FDS process facilitates the formation of additional europium-carboxylate cross-links within the polymeric network to enhance its luminescence and stability, while the FT process strengthens the network physically. The impact of the FDS-FT cycle number on the microstructures and properties of PPG/ADA-Eu3+ hydrogels is thoroughly investigated, and their potential for monitoring bacterial growth and detecting copper(II) ions is also demonstrated.
Assuntos
Alginatos , Gelatina , Hidrogéis , Alginatos/química , Hidrogéis/química , Gelatina/química , Európio/química , Reagentes de Ligações Cruzadas/química , Liofilização/métodos , Luminescência , Congelamento , Ácido Glucurônico/química , Ácidos Hexurônicos/químicaRESUMO
BACKGROUND AND OBJECTIVES: Blood safety measures used by blood establishments to increase blood component safety can be validated using Transfusion-Relevant Bacterial Reference Strains (TRBRS). Ultra-cold storage conditions and manual preparation of the current TRBRS may restrict their practical use. To address this issue, the ISBT Transfusion-Transmitted Infectious Diseases Working Party's Bacterial Subgroup organized an international study to validate TRBRS in a user-friendly, lyophilised format. MATERIALS AND METHODS: Two bacterial strains Klebsiella pneumoniae PEI-B-P-08 and Staphylococcus aureus PEI-B-P-63 were manufactured as lyophilised material. The lyophilised bacteria were distributed to 11 different labs worldwide to assess the robustness for enumeration, identification and determination of growth kinetics in platelet concentrates (PCs). RESULTS: Production of lyophilised TRBRS had no impact on the growth properties compared with the traditional format. The new format allows a direct low-quantity spiking of approximately 30 bacteria in PCs for transfusion-relevant experiments. In addition, the lyophilised bacteria exhibit long-term stability across a broad temperature range and can even be directly rehydrated in PCs without losing viability. Interlaboratory comparative study demonstrated the robustness of the new format as 100% of spiked PC exhibited growth. CONCLUSION: Lyophilised TRBRS provide a user-friendly material for transfusion-related studies. TRBRS in the new format have improved features that may lead to a more frequent use in the quality control of transfusion-related safety measures in the future.
Assuntos
Liofilização , Klebsiella pneumoniae , Staphylococcus aureus , Liofilização/métodos , Humanos , Staphylococcus aureus/crescimento & desenvolvimento , Klebsiella pneumoniae/crescimento & desenvolvimento , Segurança do Sangue/métodos , Transfusão de Sangue/métodos , Transfusão de Sangue/normas , Plaquetas/microbiologia , Padrões de Referência , Preservação de Sangue/métodosRESUMO
The objective of this study was to investigate for the first time the role of S. cerevisiae natural barriers and endogenous cytoplasmatic bodies on the stabilization of fisetin encapsulated via sonoprocessing coupled to freeze-drying (FD) or spray drying (SD). Both protocols of encapsulation improved the resistance of fisetin against thermal treatments (between 60 and 150 °C) and photochemical-induced deterioration (light exposition for 60 days) compared to non-encapsulated fisetin (antioxidant activity retention of approximately 55% and 90%, respectively). When stored under constant relative humidity (from 32.8 to 90%) for 60 days, yeast carriers improved the half-life time of fisetin by up to 4-fold. Spray dried particles were smaller (4.9 µm) and showed higher fisetin release after simulated gastrointestinal digestion (55.7%) when compared to FD. Freeze-dried particles, in turn, tended to agglomerate more than SD (zeta potential -19.7 mV), resulting in reduced loading features (6.3 mg/g) and less efficient protection of fisetin to heat, photo, and moisture-induced deterioration. Overall, spray-dried sonoprocessed fisetin capsules are an efficient way to preserve fisetin against harsh conditions. Altogether, this report shows that sonoprocessing coupled to drying is an efficient, creative, and straightforward route to protect and deliver lipophilic fisetin using yeast capsules for food applications.
Assuntos
Flavonóis , Saccharomyces cerevisiae , Cápsulas , LiofilizaçãoRESUMO
Two protein interaction peaks are observed in pharmaceutically-relevant protein (serum albumin) : disaccharide 1 : 1 and 1 : 3 (w/w) freeze-dried systems for the first time. In samples with a higher disaccharide content, the protein-protein distances are longer for both populations, while the fraction of the protein population with a shorter protein-protein distance is lower. Both factors would favor better stability against aggregation for disaccharide-rich protein formulations. This study provides direct experimental support for a "dilution" hypothesis as a potential stabilization mechanism for freeze-dried protein formulations.