A major challenge in regenerative medicine is to improve therapeutic cells' delivery and targeting using an efficient and simple protocol. Mesenchymal stem cells (MSC) are currently employed for the ...treatment of inflammatory-based diseases, due to their powerful immunosoppressive potential. Here we report a simple and versatile method to transiently overexpress the hyaluronic acid (HA) receptor, CD44, on MSC membranes, to improve their homing potential towards an inflammatory site without affecting their behavior. The effect of HA-coatings on murine MSC was functionally determined both, in vitro and in vivo as a consequence of the transient CD44 overexpression induced by HA. Data obtained from the in vitro migration assay demonstrated a two-fold increase in the migratory potential of HA-treated MSC compared to untreated cells. In an LPS-induced inflamed ear murine model, HA-treated MSC demonstrated a significantly higher inflammatory targeting as observed at 72 hrs as compared to untreated cells. This increased accumulation for HA-treated MSC yielded a substantial reduction in inflammation as demonstrated by the decrease in the expression of pro-inflammatory markers and by the induction of a pro-regenerative environment.
Despite recent advances in drug delivery, the targeted treatment of unhealthy cells or tissues continues to remain a priority. In cancer (much like other pathologies), delivery vectors are designed ...to exploit physical and biological features of unhealthy tissues that are not always homogenous across the disease. In some cases, shifting the target from unhealthy tissues to the whole organ can represent an advantage. Specifically, the natural organ-specific retention of nanotherapeutics following intravenous administration as seen in the lung, liver, and spleen can be strategically exploited to enhance drug delivery. Herein, we outline the development of a cell-based delivery system using macrophages as a delivery vehicle. When loaded with a chemotherapeutic payload (i.e., doxorubicin), these cellular vectors (CELVEC) were shown to provide continued release within the lung. This study provides proof-of-concept evidence of an alternative class of biomimetic delivery vectors that capitalize on cell size to provide therapeutic advantages for pulmonary treatments.
Human astrocytes network with neurons in dynamic ways that are still poorly defined. Our ability to model this relationship is hampered by the lack of relevant and convenient tools to recapitulate ...this complex interaction. To address this barrier, we have devised efficient coculture systems utilizing 3D organoid-like spheres, termed asteroids, containing pre-differentiated human pluripotent stem cell (hPSC)-derived astrocytes (hAstros) combined with neurons generated from hPSC-derived neural stem cells (hNeurons) or directly induced via Neurogenin 2 overexpression (iNeurons). Our systematic methods rapidly produce structurally complex hAstros and synapses in high-density coculture with iNeurons in precise numbers, allowing for improved studies of neural circuit function, disease modeling, and drug screening. We conclude that these bioengineered neural circuit model systems are reliable and scalable tools to accurately study aspects of human astrocyte-neuron functional properties while being easily accessible for cell-type-specific manipulations and observations.
•Novel three-dimensional “asteroid” coculture system is described•Complex human astrocyte-specific morphology is generated in vitro•This system produces rapid and tight association of astrocytes with synapses
In this article, Krencik and colleagues show that high-density cocultures of pre-differentiated human astrocytes with induced neurons, from pluripotent stem cells, elicit mature characteristics by 3–5 weeks. This provides a faster and more defined alternative method to organoid cultures for investigating human neural circuit function.
Nanovesicles (NVs) are emerging as innovative, theranostic tools for cargo delivery. Recently, surface engineering of NVs with membrane proteins from specific cell types has been shown to improve the ...biocompatibility of NVs and enable the integration of functional attributes. However, this type of biomimetic approach has not yet been explored using human neural cells for applications within the nervous system. Here, this paper optimizes and validates the scalable and reproducible production of two types of neuron‐targeting NVs, each with a distinct lipid formulation backbone suited to potential therapeutic cargo, by integrating membrane proteins that are unbiasedly sourced from human pluripotent stem‐cell‐derived neurons. The results establish that both endogenous and genetically engineered cell‐derived proteins effectively transfer to NVs without disruption of their physicochemical properties. NVs with neuron‐derived membrane proteins exhibit enhanced neuronal association and uptake compared to bare NVs. Viability of 3D neural sphere cultures is not disrupted by treatment, which verifies the utility of organoid‐based approaches as NV testing platforms. Finally, these results confirm cellular association and uptake of the biomimetic humanized NVs to neurons within rodent cranial nerves. In summary, the customizable NVs reported here enable next‐generation functionalized theranostics aimed to promote neuroregeneration.
Membrane proteins are extracted from either human pluripotent stem cells or differentiated neurons and combined with lipids to synthesize biomimetic nanovesicles (NVs). Neural targeting of NVs can be evaluated both in vitro using monolayer cultures and 3D organoids and in vivo by direct injection of NVs into murine trigeminal ganglions.
On 5 September 2017, a well-known 55-year-old woman journalist, Gauri Lankesh, who edited a Kannada weekly, Gauri Lankesh Patrike, was shot dead outside her home in Bangalore by gunmen mounted on ...motorcyles. The assassination sent shockwaves across the country, and let to widespread public protests. It was also condemned globally and at the United Nations. This murder demonstrated, as never before, the real threats that journalists face in modern-day India. Gauri Lankesh's murder, coming on the heels of a number of attacks on journalists, liberal thinkers, rationalists and whistle-blowers in recent months, marked a flashpoint in the debate on freedom of the media in a country that likes to describe itself as a vibrant democracy. Gauri had been a vocal critic of the communal politics seen to be pursued by the ruling Bharatiya Janata Party (BJP) and its controversial affiliate, the Rashtriya Swayamsevak Sangh.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A barrier to our understanding of how various cell types and signals contribute to synaptic circuit function is the lack of relevant models for studying the human brain. One emerging technology to ...address this issue is the use of three dimensional (3D) neural cell cultures, termed 'organoids' or 'spheroids', for long term preservation of intercellular interactions including extracellular adhesion molecules. However, these culture systems are time consuming and not systematically generated. Here, we detail a method to rapidly and consistently produce 3D cocultures of neurons and astrocytes from human pluripotent stem cells. First, pre-differentiated astrocytes and neuronal progenitors are dissociated and counted. Next, cells are combined in sphere-forming dishes with a Rho-Kinase inhibitor and at specific ratios to produce spheres of reproducible size. After several weeks of culture as floating spheres, cocultures ('asteroids') are finally sectioned for immunostaining or plated upon multielectrode arrays to measure synaptic density and strength. In general, it is expected that this protocol will yield 3D neural spheres that display mature cell-type restricted markers, form functional synapses, and exhibit spontaneous synaptic network burst activity. Together, this system permits drug screening and investigations into mechanisms of disease in a more suitable model compared to monolayer cultures.
Percutaneous aspiration and ethanol injection (PEI) is effective in managing predominantly cystic (>50% cystic) thyroid nodules with efficacy ranging from 38-85%. We aimed to evaluate efficacy, ...safety, and factors determining outcomes of PEI in managing simple cystic (purely cystic) vs. complex cystic (having both cystic and solid components) thyroid nodules.
Predominantly cystic thyroid nodules, without any ultrasonography and/or fine needle aspiration, evidence of malignancy were aspirated ultrasonography guided. Sterile 100% ethanol (50-100% volume aspirated) was injected and reviewed monthly for 3 months and thereafter 3 monthly. Responders were defined as ≥ 50% reduction in nodule volume.
Sixty-five patients out of 152 considered underwent PEI. Sixty patients simple cystic (42) and complex cystic (18) with mean follow-up of 12.3 ± 2.88 months were analyzed. Response rate of PEI was 78.33% simple cystic (92.86%) and complex cystic (44.44%) nodules; P < 0.001. Also, 31.67% patients achieved remission at 1(st) month. And, 46.67% patients achieved remission between 1-6-months follow-up. Kaplan Meier analysis showed significantly improved outcomes in patients with simple cystic nodules (P < 0.001). Cox-regression revealed type of nodule (simple cystic vs. complex cystic) to be predictive of outcome (P = 0.034). Complex cystic nodules were 67.6% less likely to go into remission, compared to simple cystic nodules. Baseline nodule size, aspirate, or volume of ethanol injected did not predict outcome.
PEI is safe and should be treatment of choice for simple cystic thyroid nodules. PEI for complex cystic thyroid nodules are associated with lower response, increased recurrence, and need for repeated PEI.
Astrocyte reactivity can directly modulate nervous system function and immune responses during disease and injury. However, the consequence of human astrocyte reactivity in response to specific ...contexts and within neural networks is obscure. Here, we devised a straightforward bioengineered neural organoid culture approach entailing transcription factor-driven direct differentiation of neurons and astrocytes from human pluripotent stem cells combined with genetically encoded tools for dual cell-selective activation. This strategy revealed that Gq-GPCR activation via chemogenetics in astrocytes promotes a rise in intracellular calcium followed by induction of immediate early genes and thrombospondin 1. However, astrocytes also undergo NF-κB nuclear translocation and secretion of inflammatory proteins, correlating with a decreased evoked firing rate of cocultured optogenetic neurons in suboptimal conditions, without overt neurotoxicity. Altogether, this study clarifies the intrinsic reactivity of human astrocytes in response to targeting GPCRs and delivers a bioengineered approach for organoid-based disease modeling and preclinical drug testing.
In the last decades, several approaches were developed to design drug delivery systems to address the multiple biological barriers encountered after administration while safely delivering a payload. ...In this scenario, bio-inspired and bio-mimetic approaches have emerged as promising solutions to evade the mononuclear phagocytic system while simultaneously negotiating the sequential transport across the various biological barriers. Leukocytes freely circulate in the bloodstream and selectively target the inflamed vasculature in response to injury, infection, and cancer. Recently we have shown the use of biomimetic nanovesicles, called leukosomes, which combine both the physical and biological properties of liposomes and leukocytes, respectively, to selectively deliver drugs to the inflamed vasculature. Here we report the use of leukosomes to target and deliver doxorubicin, a model chemotherapeutic, to tumors in syngeneic murine models of breast cancer and melanoma. Exploiting the inflammatory pathway responsible for recruiting immune cells to the site of injury, leukosomes exhibited increased targeting of cancer vasculature and stroma. Furthermore, delivery of doxorubicin with leukosomes enabled significant tumor growth inhibition compared with free doxorubicin in both breast and melanoma tumors. This study demonstrates the promise of using biomimetic nanovesicles for effective cancer management in solid tumors.
Biomimetic nanovesicles deriving from leukocytes membrane proteins, called leukosomes, exhibit increased targeting of cancer vasculature and stroma by exploiting the inflammatory pathway responsible for recruiting immune cells to the cancer lesion.
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