Pharmacokinetics and safety studies of innovative drugs is an essential part of drug development process. Previously we have developed novel drug for intravenous administration (lyophilizate) containing modified endolysin LysECD7-SMAP that showed notable antibacterial effect in different animal models of systemic infections. Here we present data on pharmacokinetics of endolysin in mice after single and multiple injections. Time-concentration curves were obtained, pharmacokinetic parameters for preparation (C0, kel t1/2, AUC0-∞, MRT, ClT, Vss) were calculated. It was shown that although endolysin is rather short-living in blood serum (t1/2 = 12.5 min) the therapeutic concentrations of LysECD7-SMAP (in degraded and non-degraded form) were detected for 60 min after injection that is sufficient for antibacterial effect. Based on the obtained data, it was proposed that endolysin distributes presumably in murine blood, degrades in blood and liver, and is eliminated via glomerular filtration. Safety profile of the preparation relating to general toxicity, immunotoxicity and allergenicity was assessed in rodents. It was demonstrated that LysECD7-SMAP in potential therapeutic (12.5 mg/kg), 10-fold (125 mg/kg) and 40-fold (500 mg/kg) doses showed no signs of intoxication and significant abnormalities after single and repeated i.v. administrations, preparation was non-immunogenic and induced minor and reversible allergic reaction in animal.

An intravenous (IV) administration of midazolam may result in seizure-like activity or movement. This report describes 5 neonates who developed seizure-like movements after IV midazolam injection. The patients presented between 2019 and 2022 and were admitted to a neonatal intensive care unit located within an academic centre in Muscat, Oman. The abnormal movements occurred shortly after IV bolus administration of midazolam. None of the patients experienced seizure-like movements after receiving midazolam infusions. The seizure-like movements were aborted either spontaneously or by antiseizure medications. In addition, seizure recurrence was not observed in any of the infants during the later stages of their treatment. Since this adverse effect might be related to the speed of the bolus administration, IV midazolam must be given as a slow bolus over 2-3 minutes followed by a slow flush of normal saline. To prevent midazolam\'s potential adverse effect on newborns, neonatal caregivers must be aware of it.

Aim: To assess mesenchymal stem cells (MSCs) as carriers for HIF-1α siRNA-loaded nanoparticles (NPs) for targeted therapy of experimental choroidal neovascularization (CNV).Materials & methods: A poly (lactic-co-glycolic acid) (PLGA)-core/lipid-shell hybrid NP was designed. The transfection efficacy of MSCs with the hybrid NPs was assessed. Mice were intravenously injected with MSCs after laser photocoagulation and CNV was assessed at 7 days post-injection.Results & conclusion: The transfection efficiency of hybrid NPs into MSCs was 72.7%. HIF-1α mRNA expression in 661w cells co-cultured with MSC-hybrid-siRNA NPs was significantly lower. Intravenous delivery of MSC-hybrid-siRNA NPs greatly reduced CNV area and length. Intravenous injection of MSC-hybrid-siRNA NPs achieved therapeutic efficacy in reducing CNV area. The MSC-mediated homing enabled targeted inhibition of ocular angiogenesis.
[Box: see text].

BACKGROUND: The aim of this study was to evaluate the adverse effects of allogeneic mesenchymal stem cells (MSCs) transplanted via intravenous infusion in dogs and examine their safety. We performed a retrospective analysis of various clinical assessments, including physical examination, blood tests, and radiographs, and monitored the formation of neoplasms during a 6-month follow-up period in 40 client-owned dogs that received intravenous infusion of adipose tissue-derived MSCs (AT-MSCs) for the treatment of various underlying diseases between 2012 and 2018.
RESULTS: No significant adverse effects of MSC therapy were detected by clinical assessment, blood tests, or radiographic examination in the 6-month follow-up period after the first MSC treatment. Additionally no new neoplasms were observed during this period.
CONCLUSIONS: To our knowledge, this study is the first to evaluate the safety aspects (≥ 6 months) associated with intravenous allogeneic AT-MSC infusion. These results suggest that allogenic AT-MSC infusion could be a useful and relatively safe therapeutic approach in canines.

Essentially all bacteria secrete nano-sized (~20-200 nm) bacterial extracellular vesicles (bEVs) loaded with proteins, lipids, glycans, and nucleic acids. bEVs facilitate interactions among cells of the same species, different microbial species, and even with cells of multicellular organisms in the context of colonization or infection. Their interactions with host organism immune cell receptors vary depending on the producing bacterial species and are now being harnessed for the development of bEVs as a potential immunotherapeutic platform. Both basic/mechanistic and preclinical therapeutic development studies are thus increasing in number and require implementation of methods for multiparametric analytical characterization as well as in vivo administration in preclinical animal models of disease. We summarize a variety of analytical methods that can be used to calculate bEV dose for preparations made from diverse bacterial sources (including sterility testing, total protein concentration, particle concentration, and lipopolysaccharide concentration). We also describe basic methodology for intravenous administration of bEV preparations via tail vein injection in laboratory mice. Throughout the description of methodology, we highlight potential pitfalls and alternatives to further equip the reader for troubleshooting should challenges arise. Robust and reproducible characterization is a prerequisite of bEV preparation quality control and consistent dosing during preclinical development. This will allow for more streamlined testing of candidate therapeutic bEVs within a given research laboratory, and furthermore facilitate reproducibility of findings across laboratories.

There are few reports of poisoning caused by high-dose intravenous injection of mercury. Its clinical manifestations are diverse and the risk of mortality is high. Currently, the pathogenesis is not clear and the treatment experience is insufficient, leading to difficulties in clinical diagnosis and treatment. In this article, the data of a case of mercury poisoning caused by intravenous self-administration was analyzed and summarized. The patient developed multiple organ dysfunction syndrome after intravenous injection of high-dose mercury. After comprehensive treatment, such as mercury removal, organ support, and infection prevention, the condition was improved. This case suggests that intravenous injection of mercury can cause damage to the functions of multiple organs, such as the heart, lungs, and kidneys. Early treatment and intervention can bring benefits.
一次性静脉注射大剂量汞引起中毒的报道很少，患者临床表现多样且汞致死风险高，目前存在发病机制不明确、治疗经验不足等问题，为临床诊疗及救治工作带来困难。本文对1例静脉注射大剂量汞引起中毒的病例资料进行整理。患者静脉注射大剂量汞后出现多器官功能障碍综合征，经过驱汞治疗、器官支持治疗、防治感染等综合救治后病情好转。提示静脉注射汞会对心脏、肺、肾等多器官功能造成损伤，早期系统干预治疗可以带来获益。.

Injection of mercury into the upper limb is a rare method of self-harm. We report two patients with varied clinical presentations - a 19-year-old male student who injected himself with mercury extracted from a sphygmomanometer bulb and reported to our emergency department 24 hours after the event and a 34-year-old industry worker who presented 2 years after injecting himself with elemental mercury. The management of mercury poisoning is described along with a brief review of literature. Mercury is a toxic element and adequate safety precautions must be taken by the surgical team in the management of such patients. Level of Evidence: Level V (Therapeutic).

BACKGROUND: Sudden sensorineural hearing loss (SSNHL), characterized by a rapid and unexplained loss of hearing, particularly at moderate to high frequencies, presents a significant clinical challenge. The therapeutic use of methylprednisolone sodium succinate (MPSS) via different administration routes, in combination with conventional medications, remains a topic of interest.
OBJECTIVE: To compare the therapeutic efficacy of MPSS administered via different routes in combination with conventional drugs for the treatment of mid- to high-frequency SSNHL.
METHODS: The medical records of 109 patients with mid- to high-frequency SSNHL were analyzed. The patients were divided into three groups based on the route of administration: Group A [intratympanic (IT) injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection], Group B (intravenous injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection), and Group C (single IT injection of MPSS). The intervention effects were compared and analyzed.
RESULTS: The posttreatment auditory thresholds in Group A (21.23 ± 3 .34) were significantly lower than those in Groups B (28.52 ± 3.36) and C (30.23 ± 4.21; P < 0.05). Group A also exhibited a significantly greater speech recognition rate (92.23 ± 5.34) than Groups B and C. The disappearance time of tinnitus, time to hearing recovery, and disappearance time of vertigo in Group A were significantly shorter than those in Groups B and C (P < 0.05). The total effective rate in Group A (97.56%) was significantly greater than that in Groups B and C (77.14% and 78.79%, χ 2 = 7.898, P = 0.019). Moreover, the incidence of adverse reactions in Groups A and C was significantly lower than that in Group B (4.88%, 3.03% vs 2.57%, χ 2 = 11.443, P = 0.003), and the recurrence rate in Group A was significantly lower than that in Groups B and C (2.44% vs 20.00% vs 21.21%, χ 2 = 7.120, P = 0.028).
CONCLUSIONS: IT injection of MPSS combined with conventional treatment demonstrates superior efficacy and safety compared to systemic administration via intravenous infusion and a single IT injection of MPSS. This approach effectively improves patients\' hearing and reduces the risk of disease recurrence.

Intravenous infusion has been used as the method of cell delivery in many preclinical studies as well as in some early clinical trials. Among its advantages are broad distribution, ability to handle a large-volume infusion, and ease of access. Progenitor cells used in cell-based therapy act through their secretomes, rather than their ability to differentiate into lineage-specific cell type. Since not all progenitor cells have similar secretome potency, the innate abilities of the secretome of cells used in clinical trials will obviously dictate their effectiveness. We previously found that cardiac neonatal mesenchymal stromal cells (nMSCs) are more effective in repairing the infarcted myocardium compared to adult mesenchymal stromal cells (aMSCs) due to their robust secretome (Sharma et al Circulation Research 120:816-834, 2017). In this study, we explored the efficacy of intravenous (IV) delivery of nMSCs for myocardial recovery. Six-week-old male Brown Norway rats underwent acute MI by ligation of the left anterior descending artery, followed by IV infusion of cell dose 5 × 106 nMSCs/rat body weight (kg) or saline on days 0 and 5. We found that cardiac parameters in the rodent ischemia model improved 1 month after nMSCs infusion, and the result is comparable with the intramyocardial injection of nMSCs. Tracking the infused cells in target organ revealed that their movement after IV delivery was mediated by the cell surface receptor CD44. Systemic injection of nMSCs stimulated immunomodulatory responses specifically by increasing FoxP3+ T-regulatory cell influenced anti-inflammatory macrophages (M2) in heart. These data demonstrate that nMSCs promote immunogenic tolerance via CD44-driven T-reg/M2 stimulation that helps nMSCs for longer viability in the injured myocardium for better functional recovery. Our data also demonstrate a rationale for a clinical trial of IV infusion of nMSCs to promote cardiac function improvement in the ischemic patients.

BACKGROUND: Although umbilical cord mesenchymal stem cell (UCMSC) infusion has been proposed as a promising strategy for the treatment of acute lung injury (ALI), the parameters of UCMSC transplantation, such as infusion routes and doses, need to be further optimized.
METHODS: In this study, we compared the therapeutic effects of UCMSCs transplanted via intravenous injection and intratracheal instillation on lipopolysaccharide-induced ALI using a rat model. Following transplantation, levels of inflammatory factors in serum; neutrophils, total white blood cells, and lymphocytes in bronchoalveolar lavage fluid (BALF); and lung damage levels were analyzed.
RESULTS: The results indicated that UCMSCs administered via both intravenous and intratracheal routes were effective in alleviating ALI, as determined by analyses of arterial blood gas, lung histopathology, BALF contents, and levels of inflammatory factors. Comparatively, the intratracheal instillation of UCMSCs was found to result in lower levels of lymphocytes and total proteins in BALF, whereas greater reductions in the serum levels of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were detected in rats receiving intravenously injected stem cells.
CONCLUSIONS: Our findings in this study provide convincing evidence to indicate the efficacy of UCMSC therapy in the treatment of ALI mediated via different delivery routes, thereby providing a reliable theoretical basis for further clinical studies. Moreover, these findings imply that the effects obtained using the two assessed delivery routes for UCMSC transplantation are mediated via different mechanisms, which could be attributable to different cellular or molecular targets.