Human Blood Components Research Articles

Thrombin contributes to protective immunity in pneumonia‐derived sepsis via fibrin polymerization and platelet–neutrophil interactions

Background Innate immunity and coagulation are closely linked during sepsis. Their interaction can be detrimental to the outcome because of microvascular failure but can also enhance host defense. The role of thrombin therein has not been fully elucidated. Objective We aimed to investigate the contribution of thrombin to the host response during pneumonia-derived sepsis. Methods Mice treated with the specific thrombin inhibitor dabigatran or control chow were infected with the common human sepsis pathogen Klebsiella (K.) pneumoniae via the airways. In subsequent infection experiments, mice were additionally treated with ancrod to deplete fibrinogen. Ex vivo Klebsiella growth was assessed by incubating human whole blood or specific blood components in various conditions with Klebsiella. Results Thrombin inhibition by dabigatran enhanced bacterial outgrowth and spreading, and accelerated mortality. Thrombin inhibition did not influence neutrophil recruitment to the lung or activation or neutrophil extracellular trap formation. Dabigatran reduced D-dimer formation and fibrin deposition in the lung. Fibrin depletion also enhanced bacterial outgrowth and spreading, and thrombin inhibition had no additional effect. Both thrombin and fibrin polymerization inhibited ex vivo Klebsiella outgrowth in human whole blood, which was neutrophil dependent, and the effect of thrombin required the presence of platelets and platelet protease activated receptor-1. In vivo thrombin inhibition reduced platelet-neutrophil complex formation and endothelial cell activation, but did not prevent sepsis-induced thrombocytopenia or organ damage. Conclusions These results suggest that thrombin plays an important role in protective immunity during pneumonia-derived sepsis by fibrin polymerization and enhancement of platelet-neutrophil interactions.

Preclinical Safety Studies of Enadenotucirev, a Chimeric Group B Human-Specific Oncolytic Adenovirus

Enadenotucirev is an oncolytic group B adenovirus identified by a process of bio-selection for the ability to selectively propagate in and rapidly kill carcinoma cells. It is resistant to inactivation by human blood components, potentially enabling intravenous dosing in patients with metastatic cancer. However, there are no known permissive animal models described for group B adenoviruses that could facilitate a conventional approach to preclinical safety studies. In this manuscript, we describe our tailored preclinical strategy designed to evaluate the key biological properties of enadenotucirev. As enadenotucirev does not replicate in animal cells, a panel of primary human cells was used to evaluate enadenotucirev replication selectivity in vitro, demonstrating that virus genome levels were >100-fold lower in normal cells relative to tumor cells. Acute intravenous tolerability in mice was used to assess virus particle-mediated toxicology and effects on innate immunity. These studies showed that particle toxicity could be ameliorated by dose fractionation, using an initial dose of virus to condition the host such that cytokine responses to subsequent doses were significantly attenuated. This, in turn, supported the initiation of a phase I intravenous clinical trial with a starting dose of 1 × 1010 virus particles given on days 1, 3, and 5.

Survival of Carbapenem-Resistant Klebsiella pneumoniae Sequence Type 258 in Human Blood.

Klebsiella pneumoniae is a prominent cause of nosocomial infections worldwide. Bloodstream infections caused by carbapenem-resistant K. pneumoniae, including the epidemic lineage known as multilocus sequence type 258 (ST258), are difficult to treat, and the rate of mortality from such infections is high. Thus, it is imperative that we gain a better understanding of host defense against this pathogen as a step toward developing novel therapies. Here we tested the hypothesis that the resistance of ST258 to bactericidal components of human blood, such as serum complement, is linked to virulence capacity in the context of bacteremia. There was significant variance in the survival of ST258 clinical isolates in heparinized human blood or normal human serum. The rate of survival of ST258 isolates in human blood was, in general, similar to that in normal human serum, suggesting a prominent role for complement (rather than leukocytes) in the healthy host defense against ST258 isolates and related organisms. Indeed, deposition of serum complement-the C5b to C9 (C5b-C9) membrane attack complex-onto the surface of ST258 isolates accompanied serum bactericidal activity. Human serum treated with pharmacological inhibitors of complement, depleted of antibody, or heated at 56°C for 30 min had significantly reduced or absent bactericidal activity. In contrast to heparinized blood from humans, that from BALB/c mice lacked bactericidal activity toward the ST258 isolates tested, but the virulence of these ST258 isolates in a mouse bacteremia model was inexplicably limited. Our data highlight the importance of the complement system in host defense against ST258 bacteremia, and we propose that there is the potential to enhance complement-mediated bactericidal activity using an antibody-based approach.

Research Progress on the Risk Factors and Outcomes of Human Carotid Atherosclerotic Plaques.

Objective:Atherosclerosis is an inflammatory process that results in complex lesions or plaques that protrude into the arterial lumen. Carotid atherosclerotic plaque rupture, with distal atheromatous debris embolization, causes cerebrovascular events. This review aimed to explore research progress on the risk factors and outcomes of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention.Data Sources:We searched the PubMed database for recently published research articles up to June 2016, with the key words of “risk factors”, “outcomes”, “blood components”, “molecular mechanisms”, “cellular mechanisms”, and “human carotid atherosclerotic plaques”.Study Selection:The articles, regarding the latest developments related to the risk factors and outcomes, atherosclerotic plaque composition, blood components, and consequences of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention, were selected.Results:This review described the latest researches regarding the interactive effects of both traditional and novel risk factors for human carotid atherosclerotic plaques, novel insights into human carotid atherosclerotic plaque composition and blood components, and consequences of human carotid atherosclerotic plaque.Conclusion:Carotid plaque biology and serologic biomarkers of vulnerability can be used to predict the risk of cerebrovascular events. Furthermore, plaque composition, rather than lesion burden, seems to most predict rupture and subsequent thrombosis.

Biocorona Bound Gold Nanoparticles Augment Their Hematocompatibility Irrespective of Size or Surface Charge.

Despite colloidal gold nanoparticles (AuNP) being proposed for a multitude of biomedical applications, there is a lack of understanding on how the protein corona (PC) formation over AuNP influences its interaction with blood components. Herein, 40 and 80 nm AuNP with branched polyethylenimine, lipoic acid, and polyethylene glycol surface coatings were exposed to human plasma, and time-dependent evolution of the PC was evaluated using differential centrifugation sedimentation. Further, the impact of PC-AuNP interaction with human blood components was studied by evaluating red blood cell (RBC) aggregation, hemolysis, platelet activation and aggregation, prothrombin time, activated partial thromboplastin time, complement activation and cytokine release. In contrast to bare AuNP, PC-coated AuNP exhibited enhanced compatibility with RBC, platelets, and lymphocytes. More importantly, PC-AuNP did not activate the platelet coagulation cascade or complement system or elicit an immune response up to a relatively higher dose of 100 μg/mL. This study suggests that, irrespective of the physicochemical properties, the adsorption of the PC over AuNP significantly influences its biological impact by alleviating adverse hematotoxicity of bare NP.

Nanodiamonds for Medical Applications: Interaction with Blood in Vitro and in Vivo.

Nanodiamonds (ND) have emerged to be a widely-discussed nanomaterial for their applications in biological studies and for medical diagnostics and treatment. The potentials have been successfully demonstrated in cellular and tissue models in vitro. For medical applications, further in vivo studies on various applications become important. One of the most challenging possibilities of ND biomedical application is controllable drug delivery and tracing. That usually assumes ND interaction with the blood system. In this work, we study ND interaction with rat blood and analyze how the ND surface modification and coating can optimize the ND interaction with the blood. It was found that adsorption of a low concentration of ND does not affect the oxygenation state of red blood cells (RBC). The obtained in vivo results are compared to the results of in vitro studies of nanodiamond interaction with rat and human blood and blood components, such as red blood cells and blood plasma. An in vivo animal model shows ND injected in blood attach to the RBC membrane and circulate with blood for more than 30 min; and ND do not stimulate an immune response by measurement of proinflammatory cytokine TNF-α with ND injected into mice via the caudal vein. The results further confirm nanodiamonds’ safety in organisms, as well as the possibility of their application without complicating the blood’s physiological conditions.

Spectrophotometric Study of the Effect of a Magnetic Field on Human Blood Components

We have used electronic spectroscopy and optical aggregometry to study the effect of a constant magnetic fi eld on blood components. Based on the absorption spectra, we observe a decrease in optical density for both plasma and whole blood samples. Based on the results of platelet aggregation studies, we identifi ed two groups of test subjects with opposite types of responses to exposure to a magnetic fi eld. The observed behavior is probably associated with changes in the spatial structure of the proteins.

Pseudocatalytic scavenging of the nerve agent VX with human blood components and the oximes obidoxime and HI-6.

Despite six decades of extensive research in medical countermeasures against nerve agent poisoning, a broad spectrum acetylcholinesterase (AChE) reactivator is not yet available. One current approach is directed toward synthesizing oximes with high affinity and reactivatability toward butyrylcholinesterase (BChE) in plasma to generate an effective pseudocatalytic scavenger. An interim solution could be the administration of external AChE or BChE from blood products to augment pseudocatalytic scavenging with slower but clinically approved oximes to decrease nerve agent concentrations in the body. We here semiquantitatively investigate the ability of obidoxime and HI-6 to decrease the inhibitory activity of VX with human AChE and BChE from whole blood, erythrocyte membranes, erythrocytes, plasma, clinically available fresh frozen plasma and packed red blood cells. The main findings are that whole blood showed a VX concentration-dependent decrease in inhibitory activity with HI-6 being more potent than obidoxime. Using erythrocytes and erythrocyte membranes again, HI-6 was more potent compared to obidoxime. With freshly prepared plasma, obidoxime and HI-6 showed comparable results for the decrease in VX. The use of the clinically available blood products revealed that packed red blood cells showed similar kinetics as fresh erythrocytes. Fresh frozen plasma resulted in a slower and incomplete decrease in inhibitory plasma compared to freshly prepared plasma. In conclusion, the administration of blood products in combination with available oximes augments pseudocatalytic scavenging and might be useful to decrease the body load of persistent, highly toxic nerve agents.

Correction: PCR-Free Enrichment of Mitochondrial DNA from Human Blood and Cell Lines for High Quality Next-Generation DNA Sequencing

[This corrects the article DOI: 10.1371/journal.pone.0139253.].

Blood compatibility evaluations of poly(ethylene glycol)-poly(lactic acid) copolymers.

Poly(ethylene glycol)-poly(lactic acid) (PEG-PLA) copolymers have been widely used for various biomedical applications. However, their hemocompatibility has not been clarified, which would lag their developments and clinical applications. In this work, we studied the effect of PEG-PLA copolymers on key human blood components in terms of their structure and bio-functions, including morphology and lysis of red blood cells, fibrinogen structure and conformation, and plasma and blood coagulation. To elucidate a structure-activity relationship, we used diblock PEG-PLA copolymers with different molecular weight, PEG(5 kDa)-PLA(25 kDa) and PEG(2 kDa)-PLA(2 kDa), abbreviated as PEG5k-PLA25k and PEG2k-PLA2k, respectively. The results show that the PEG-PLA copolymers at the concentration range studied in this work neither caused morphological alteration and lysis of red blood cells nor affected the oxygen delivery function and fibrinogen conformation. PEG5k-PLA25k from 10 to 100 mg/mL and PEG2k-PLA2k from 1.5 to 5 mg/mL disturbed the local microenvironments of fibrinogen molecules. PEG5k-PLA25k at up to 0.1 mg/mL did not interfere in the coagulation process of plasma or whole blood, while PEG2k-PLA2k from 0.1 mg/mL significantly interfered in the intrinsic plasma coagulation pathway and impaired whole blood coagulation. The results provide important information for the molecular design and clinical applications of PEG-PLA copolymers.

Bone grafts and bone substitutes in dentistry

Bone resorption is a natural phenomenon and can occur due to old age, loss of teeth, prolonged denture wear, or as a result of systemic conditions. For the replacement of teeth by fabrication of prosthesis or the use of implants, a minimum amount of bone density is required. Bone grafting is a method by which bone-deficient areas are built up, with the use of different materials, such as autografts, allografts, alloplasts, and xenografts. Over recent times, the use of frozen bone matrix formulations and synthetic ceramics has been used in greater frequency. This article discusses the use of human bone material (allografts), synthetic materials (alloplasts) and blood components as successful grafting materials. Their use has shown an effective amount of bone formation and proliferation in the defective sites and proves to be a beneficial choice in bringing back lost bone.

Distribution and survival of Borrelia miyamotoi in human blood components

Borrelia miyamotoi, the agent of relapsing fever, is a tick-borne spirochete first isolated in Japan in 1994. Since then, the spirochete has been detected in ticks globally, generally in the same vectors as the Lyme disease agent. Human infection has been reported in Russia, Europe, Japan, and the United States, as influenza-like febrile illness. In addition, two cases of meningoencephalitis caused by B. miyamotoi have also been reported in immunocompromised patients. Here we evaluate the ability of the spirochete to survive in human blood components stored under standard blood bank conditions. Freshly collected human whole blood was spiked with in vitro cultured B. miyamotoi or B. miyamotoi-infected mouse plasma and separated into red blood cells (RBCs), plasma, and platelets. Components were either injected into immunocompromised (SCID) or wild-type immunocompetent mice or cultured in vitro, right after separation and after storage at the appropriate conditions. Infection was monitored by microscopic observation, blood smears, and polymerase chain reaction. In vivo, all the SCID mice challenged with the components before storage and the RBCs stored for up to 42 days developed the infection. Wild-type mice also developed the infection when injected with prestorage samples from all components, while a lower number of mice were infected by RBCs stored for 42 days. In vitro, spirochetes grew in all samples but frozen plasma. This study demonstrated that B. miyamotoi can survive standard storage conditions of most human blood components, suggesting the possibility of transmission by blood transfusion.

A Targeted Photochemical Microfluidic Vascular Injury Model for in Vitro Thrombosis Studies: Usage in Heparin-Induced Thrombocytopenia (HIT)

Replicating the complexities of the human blood vessel include the establishment of a 3-D confluency of viable endothelial cells (ECs) on an appropriate matrix, use of human whole blood or specific components of blood, varied shear stresses, and the induction of a localized and controlled injury within the observable field to understand and intervene in hemostatic events. This array of complexities have made vascular modeling an important unmet challenge. Such a model would enhance our understanding of the pathogenesis of diverse coagulation disorders, such as the prothrombotic disorder HIT. In HIT, the platelet-rich clots lead to its other designation as the "white clot syndrome". To provide an improved injury model, we adapted a hematoporphyrin-photochemical injury using a Fluxion Bioflux microfluidic system. When illuminated with 405 nm light, hematoporphyrin releases reactive oxygen species, inducing localized EC injury within the exposed field, but without denuding ECs. Unlike rose bengal, hematoporphyrin does not cause fluorescent interference with quantitative analysis of the developing thrombus. We propose that the model permits refined analysis of ECs transitioning from areas of quiescence to injury to quiescence, allowing us to localize and quantify the contribution of various components to the growing thrombus. In HIT, patients form antibodies to complexes of the platelet-specific chemokine, platelet factor 4 (PF4), and negatively-charged molecules such as infused heparin and heparans found on the surface of platelets and monocytes. ECs also bind PF4 immune complexes due to their highly negatively charged glycocalyx-rich surface. Prior murine cremaster laser injury studies showed that HIT antibodies bind predominantly to the EC surface rather than platelet within the thrombus itself. Was this observation related to the nature of the cremaster injury? Would antibody binding to the EC lining also be important in a wholly human HIT detection system? Using the described photochemical microfluidic system, we created a localized injury in human umbilical vein EC-lined channels through which we flowed whole human blood. Activated platelets established growing aggregates at the site of EC injury, releasing more PF4 that then bound to non-activated ECs downstream of the injury. Whole blood containing a HIT-like antibody to simulate the prothrombotic state of HIT was then flowed over this injured vasculature. HIT antibodies and then platelets bound sequentially to this new site of HIT antigen, allowing the thrombus to propagate downstream. We have named this phenomenon "rolling barrage" and suggest that a key part of the prothrombotic nature of HIT lies in antibody-mediated activation of downstream EC with subsequent thrombus propagation. HIT often occurs in the setting in surgery, which might prime EC dysfunction. We therefore treated the ECs (TNF-α) prior to injury and introducing the HIT-like antibody. TNF-α activated the EC lining, leading to loss of the anticoagulant EC surface, which enhanced clot formation downstream of the site of photochemical injury. Therefore, in a prothrombotic state such as HIT, we propose that a local injury acts as a nidus for thrombus initiation. The procoagulant process spreads distally in part because of released PF4 adhering to the downstream EC glycocalyx, which is exacerbated by mediators of inflammation. We anticipate that the described model can be used to study novel interventions to block this cycle in a wholly human system with control over the contribution of individual cellular elements, and will further understanding of the importance of this mechanism in other prothrombotic disorders. DisclosuresNo relevant conflicts of interest to declare.

PCR-Free Enrichment of Mitochondrial DNA from Human Blood and Cell Lines for High Quality Next-Generation DNA Sequencing.

Recent advances in sequencing technology allow for accurate detection of mitochondrial sequence variants, even those in low abundance at heteroplasmic sites. Considerable sequencing cost savings can be achieved by enriching samples for mitochondrial (relative to nuclear) DNA. Reduction in nuclear DNA (nDNA) content can also help to avoid false positive variants resulting from nuclear mitochondrial sequences (numts). We isolate intact mitochondrial organelles from both human cell lines and blood components using two separate methods: a magnetic bead binding protocol and differential centrifugation. DNA is extracted and further enriched for mitochondrial DNA (mtDNA) by an enzyme digest. Only 1 ng of the purified DNA is necessary for library preparation and next generation sequence (NGS) analysis. Enrichment methods are assessed and compared using mtDNA (versus nDNA) content as a metric, measured by using real-time quantitative PCR and NGS read analysis. Among the various strategies examined, the optimal is differential centrifugation isolation followed by exonuclease digest. This strategy yields >35% mtDNA reads in blood and cell lines, which corresponds to hundreds-fold enrichment over baseline. The strategy also avoids false variant calls that, as we show, can be induced by the long-range PCR approaches that are the current standard in enrichment procedures. This optimization procedure allows mtDNA enrichment for efficient and accurate massively parallel sequencing, enabling NGS from samples with small amounts of starting material. This will decrease costs by increasing the number of samples that may be multiplexed, ultimately facilitating efforts to better understand mitochondria-related diseases.

Homosexuals and blood donation: a delicate issue for the European Union Court of Justice.

On 29 April, 2015, the European Union (EU) Court of Justice in Luxembourg had to rule a delicate issue: to decide on a French bylaw, banning homosexuals from eligibility to donate blood on a permanent basis as their sexual behaviour may cause a high risk of acquiring severe infectious diseases, transmitted by blood1. The issue was delicate since such a ban categorically excludes a category of citizens from donating blood, which might be contrary to fundamental human rights such as the equal treatment and non-discrimination principle, recognised by EU law. Secondly, as the Court was requested to rule on an issue that concerns the exclusive competence of individual member states: the organisation and delivery of health services and medical care. Despite the member states’ exclusive competences, the EU has some limited role in terms of blood donation by setting standards of quality and safety of human blood and blood components, as established by the so-called Blood Donation Directive2,3. This short report explains the Court’s reasoning, reviewing the conformity of member states’ legislation on blood donation with EU law. Secondly, the Author addresses the relevance to other EU member states.

Effect of cyclodextrins on the structure and functions of blood components in vitro

Cyclodextrins have been extensively used in various biomedical and pharmaceutical applications. In these applications, cyclodextrins administered in vivo would inevitably enter blood stream. However, there is not enough information on the hemocompatibility of cyclodextrins until now. In this study, we investigated the influences of cyclodextrins (α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin) on human blood components and functions in vitro, that is, morphology and lysis of red blood cells, structure and conformation of fibrinogen, complement activation, and blood coagulation. It was found that 10 mg/mL of α- or β-cyclodextrins caused abnormal red blood cell morphology and serious hemolysis, while γ-cyclodextrin at 10 mg/mL did not impair red blood cell membrane morphology and integrity. The three cyclodextrins at up to 10 mg/mL affected the local microstructure but did not change the conformation of fibrinogen. The three cyclodextrins from 0.01 to 1 mg/mL all significantly activated the complement system in a concentration-dependent way. The three cyclodextrins at up to 5 mg/mL in blood plasma did not cause significantly different coagulation times compared with the negative control. In addition, the three cyclodextrins at up to 5 mg/mL in whole blood did not cause abnormal coagulation parameters. These results provide significant information on blood safety of the three cyclodextrins for their biomedical and pharmaceutical applications.

Interactions of stealth conjugated polymer nanoparticles with human whole blood.

Photoluminescent conjugated polymeric nanoparticles (CPNs) exhibit favourable properties as fluorescent probes due to their brightness, high photostability, tunable emission spectra and ease of surface modification. Potential cellular and clinical applications of these new diagnostic agents are easily envisioned, providing a rationale to study CPN biocompatibility. Here, stealth formulations of poly phenylene vinylene (PPV) and poly phenylene ethinylene (PPE) were manufactured and their interactions with human blood components assessed. CPNs were colloidally stable in isotonic fluids, but showed photoluminescence quenching in whole blood and plasma at levels as low as 10% supplementation. At concentrations >150 μg mL-1, stealth CPNs caused ∼10% erythrocyte haemolysis, which was likely due to unbound pegylated surfactant present in the formulation. Incubation of CPNs with both whole blood and isolated platelets showed no platelet activation, increases in platelet-monocyte aggregates or induction of platelet aggregation. Interestingly, PPE-CPN formulations inhibited adenosine diphosphate (ADP)-induced platelet aggregation in a dose-dependent manner, while PPV-CPNs did not show this effect. In conclusion, stealth CPN formulations exhibiting neutrally charged, pegylated surfaces do not stimulate platelet activation or aggregation, but may induce a low degree of haemolysis in the presence of free surfactant and can inhibit physiological mediators of platelet aggregation, such as ADP.

Impact of Ficoll density gradient centrifugation on major and trace element concentrations in erythrocytes and blood plasma

ProjectFicoll density gradient centrifugation is widely used to separate cellular components of human blood. We evaluated the suitability to use erythrocytes and blood plasma obtained from Ficoll centrifugation for assessment of elemental concentrations. ProcedureWe determined 22 elements (from Li to U) in erythrocytes and blood plasma separated by direct or Ficoll density gradient centrifugation, using inductively coupled plasma mass spectrometry. ResultsCompared with erythrocytes and blood plasma separated by direct centrifugation, those separated by Ficoll had highly elevated iodine and Ba concentration, due to the contamination from the Ficoll-Paque medium, and about twice as high concentrations of Sr and Mo in erythrocytes. On the other hand, the concentrations of Ca in erythrocytes and plasma were markedly reduced by the Ficoll separation, to some extent also Li, Co, Cu, and U. The reduced concentrations were probably due to EDTA, a chelator present in the Ficoll medium. Arsenic concentrations seemed to be lowered by Ficoll, probably in a species-specific manner. The concentrations of Mg, P, S, K, Fe, Zn, Se, Rb, and Cs were not affected in the erythrocytes, but decreased in plasma. Concentrations of Mn, Cd, and Pb were not affected in erythrocytes, but in plasma affected by EDTA and/or pre-analytical contamination. ConclusionsFicoll separation changed the concentrations of Li, Ca, Co, Cu, As, Mo, I, Ba, and U in erythrocytes and blood plasma, Sr in erythrocytes, and Mg, P, S, K, Fe, Zn, Se, Rb and Cs in blood plasma, to an extent that will invalidate evaluation of deficiencies or excess intakes.

Inactivation of the antibacterial and cytotoxic properties of silver ions by biologically relevant compounds.

There has been a recent surge in the use of silver as an antimicrobial agent in a wide range of domestic and clinical products, intended to prevent or treat bacterial infections and reduce bacterial colonization of surfaces. It has been reported that the antibacterial and cytotoxic properties of silver are affected by the assay conditions, particularly the type of growth media used in vitro. The toxicity of Ag+ to bacterial cells is comparable to that of human cells. We demonstrate that biologically relevant compounds such as glutathione, cysteine and human blood components significantly reduce the toxicity of silver ions to clinically relevant pathogenic bacteria and primary human dermal fibroblasts (skin cells). Bacteria are able to grow normally in the presence of silver nitrate at >20-fold the minimum inhibitory concentration (MIC) if Ag+ and thiols are added in a 1∶1 ratio because the reaction of Ag+ with extracellular thiols prevents silver ions from interacting with cells. Extracellular thiols and human serum also significantly reduce the antimicrobial activity of silver wound dressings Aquacel-Ag (Convatec) and Acticoat (Smith & Nephew) to Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in vitro. These results have important implications for the deployment of silver as an antimicrobial agent in environments exposed to biological tissue or secretions. Significant amounts of money and effort have been directed at the development of silver-coated medical devices (e.g. dressings, catheters, implants). We believe our findings are essential for the effective design and testing of antimicrobial silver coatings.

Raising the standard: changes to the Australian Code of Good Manufacturing Practice (cGMP) for Human Blood and Blood Components, Human Tissues and Human Cellular Therapy Products

In Australia, manufacture of blood, tissues and biologicals must comply with the federal laws and meet the requirements of the Therapeutic Goods Administration (TGA) Manufacturing Principles as outlined in the current Code of Good Manufacturing Practice (cGMP). The Therapeutic Goods Order (TGO) No. 88 was announced concurrently with the new cGMP, as a new standard for therapeutic goods. This order constitutes a minimum standard for human blood, tissues and cellular therapeutic goods aimed at minimising the risk of infectious disease transmission. The order sets out specific requirements relating to donor selection, donor testing and minimisation of infectious disease transmission from collection and manufacture of these products. The Therapeutic Goods Manufacturing Principles Determination No. 1 of 2013 references the human blood and blood components, human tissues and human cellular therapy products 2013 (2013 cGMP). The name change for the 2013 cGMP has allowed a broadening of the scope of products to include human cellular therapy products. It is difficult to directly compare versions of the code as deletion of some clauses has not changed the requirements to be met, as they are found elsewhere amongst the various guidelines provided. Many sections that were specific for blood and blood components are now less prescriptive and apply to a wider range of cellular therapies, but the general overall intent remains the same. Use of 'should' throughout the document instead of 'must' allows flexibility for alternative processes, but these systems will still require justification by relevant logical argument and validation data to be acceptable to TGA. The cGMP has seemingly evolved so that specific issues identified at audit over the last decade have now been formalised in the new version. There is a notable risk management approach applied to most areas that refer to process justification and decision making. These requirements commenced on 31 May 2013 and a 12 month transition period applies for implementation by manufacturers. The cGMP and TGO update follows the implementation of the TGA regulatory biologicals framework for cell and tissue based therapies announced in 2011. One implication for licenced TGA facilities is that they must implement the 2013 cGMP, TGO 88 and other relevant TGOs together, as they are intricately linked. This review is intended to assist manufacturers by comparing the 2000 version of the cGMP, to the new 2013 cGMP, noting that the new Code extends to include human cellular therapy products.