Objective Chronic wound healing, particularly in diabetic wounds, remains challenging due to the lack of effective therapeutic procedures. Pharmacological treatments are often limited by physical side effects, while surgical procedures carry a risk of site infections. This study aimed to provide an overall complete therapeutic regimen for faster diabetic wound healing through focused ultrasound (FUS) in conjunction with localized copper-cystine biohybrids. Methods In the current study, we investigated the feasibility of combining FUS performed at 1 MPa, 2500 cycles, 10% duty cycle, 20 Hz pulse repetition frequency and 15-min treatment durations every alternate day over 14 d with localized copper-cystine biohybrid (copper high aspect ratio structures [CuHARS]) treatment, which is a metal-organic biohybrid capable of promoting angiogenesis and exerting a bactericidal effect on wound healing. Therapeutic efficacy was evaluated in diabetic mice with surgically induced dermal wounds using three treatment groups: combined CuHARS-FUS, CuHARS-only and FUS-only over 7- and 14-d periods. Results The results showed that CuHARS-FUS treatment for 14 ds achieved complete wound closure, whereas the CuHARS-only, FUS-only and control groups exhibited partial or no healing. Conclusion The synergistic treatment of CuHARS-FUS supports rapid macrovascular structure formation and proper cellular differentiation, leading to granulation tissue formation by providing a controlled mechanism for tissue remodeling during the entire healing phase of diabetic wound healing, starting from an enhanced angiogenic activity and bactericidal effect via the CuHARS through Cu2+ ions-based catalytic decomposition of S-nitrosothiols to nitric oxide and the continuation of endothelial activity through enhanced nitric oxide production due to FUS treatment.
We have previously described the generation of Metal Organic Biohybrids (MOBs) as self-assembling structures that are formed by a combination of a biological component (amino acid), and a metal, such as copper. This MOBs synthesis process has now been distilled to be purely biochemical (a green chemistry process), or abiotic, not requiring the presence of cells. Building on these discoveries, in this commentary we describe the use of selenium for the first time using MOBs synthesis techniques, as well as using biotic techniques, that is, selenium in the presence of living microbes. New and different materials are described using the respective techniques, which have different nano- and micro-scale properties. We anticipate that the abiotic and biotic techniques may provide parallel methods for generating new MOBs and new nanomaterials, respectively. One potential application of the generated materials could include treatments for cancer, since in the case of selenium-containing MOBs, we demonstrate 100 percent biodegradability.
The microstructural features, electrochemical corrosion behavior, and biocompatibility with Locke's solution were evaluated for 316L stainless steel (SS) samples fabricated by selective laser melting (SLM) with understudied processing conditions providing low residual stress - 800, 1000 and 1200 mm/s laser scan speed with a laser power of 100 W. Confocal images and scanning electron microscopy found fewer SLM processing induced surface flaws at samples fabricated at 800 mm/s. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements indicated samples fabricated at 800 mm/s developed a more compact and thicker passive oxide film resulting in greater corrosion resistance, relative to samples prepared at the higher laser scan speeds. The surface characteristics of SLM 316L SS samples fabricated at 800 mm/s also promoted substantial biocompatibility that was observed via cell attachment and differentiation of osteoblasts, as well as high collagen 1A coverage indicating strong potential as a alternative implant material.
Copper-cystine-based high aspect ratio structures (CuHARS) possess exceptional physical and chemical properties and exhibit remarkable biodegradability in human physiological conditions. Extensive testing has confirmed the biocompatibility and biodegradability of CuHARS under diverse biological conditions, making them a viable source of essential Cu2+. These ions are vital for catalyzing the production of nitric oxide (NO) from the decomposition of S-nitrosothiols (RSNOs) found in human blood. The ability of CuHARS to act as a Cu2+ donor under specific concentrations has been demonstrated in this study, resulting in the generation of elevated levels of NO. Consequently, this dual function makes CuHARS effective as both a bactericidal agent and a promoter of angiogenesis. In vitro experiments have shown that CuHARS actively promotes the migration and formation of complete lumens by redirecting microvascular endothelial cells. To maximize the benefits of CuHARS, they have been incorporated into biomimetic electrospun poly(ε-caprolactone)/gelatin nanofiber aerogels. Through the regulated release of Cu2+ and NO production, these channeled aerogels not only provide antibacterial support but also promote angiogenesis. Taken together, the inclusion of CuHARS in biomimetic scaffolds could hold great promise in revolutionizing tissue regeneration and wound healing.
Following traumatic brain injury (TBI), secondary brain damage due to chronic inflammation is the most predominant cause of the delayed onset of mood and memory disorders. Currently no therapeutic approach is available to effectively mitigate secondary brain injury after TBI. One reason is the blood-brain barrier (BBB), which prevents the passage of most therapeutic agents into the brain. Peptides have been among the leading candidates for CNS therapy due to their low immunogenicity and toxicity, bioavailability, and ease of modification. In this study, we demonstrated that non-invasive intranasal (IN) administration of KAFAK, a cell penetrating anti-inflammatory peptide, traversed the BBB in a murine model of diffuse, moderate TBI. Notably, KAFAK treatment reduced the production of proinflammatory cytokines that contribute to secondary injury. Furthermore, behavioral tests showed improved or restored neurological, memory, and locomotor performance after TBI in KAFAK-treated mice. This study demonstrates KAFAK's ability to cross the blood-brain barrier, to lower proinflammatory cytokines in vivo, and to restore function after a moderate TBI.
Alzheimer's Disease (AD) patients experience diverse symptoms, including memory loss, cognitive impairment, behavioral abnormalities, mood changes, and mental issues. The fundamental objective of this review is to discuss novel therapeutic approaches, with special emphasis on recently approved marketed formulations for the treatment of AD, especially Aducanumab, the first FDA approved moiety that surpasses the blood-brain barrier (BBB) and reduces amyloid plaques in the brain, thereby reducing associated cognitive decline. However, it is still in the phase IV trial and is to be completed by 2030. Other drugs such as lecanemab are also under clinical trial and has recently been approved by the FDA and is also discussed here. In this review, we also focus on active and passive immunotherapy for AD as well as several vaccines, such as amyloid-beta epitope-based vaccines, amyloid-beta DNA vaccines, and stem cell therapy for AD, which are in clinical trials. Furthermore, ongoing pre-clinical trials associated with AD and other novel strategies such as curcumin-loaded nanoparticles, Crispr/ cas9, precision medicine, as well as some emerging therapies like anti-sense therapy are also highlighted. Additionally, we discuss some off-labeled drugs like non-steroidal anti-inflammatory drugs (NSAID), anti-diabetic drugs, and lithium, which can manage symptoms of AD and different non-pharmacological approaches are also covered which can help to manage AD. In summary, we have tried to cover all the therapeutic interventions which are available for the treatment and management of AD under sections approved, clinical phase, pre-clinical phase or futuristic interventions, off-labelled drugs, and non-pharmacological interventions for AD, offering positive findings and well as challenges that remain.
Copper is involved in the biosynthesis of collagen, however soluble copper salts dissipate quickly and copper nanoparticles are cytotoxic. Here we added a novel copper-containing nanomaterial (CuHARS) to assess human chondrocyte function in the presence of copper. Human dermal fibroblasts (HDFs) were also treated as a control. Chondrocyte response to CuHARS was assessed by chronic nanomaterial treatment (30 µg/ml) followed by digital microscopy and image analysis of cellular features compared to normal chondrocytes. Unexpectedly, chronic CuHARS treatment of human chondrocytes transformed cells over time to cells with extremely elongated and variegated processes and lower proliferation rates compared to normal chondrocytes. In these transformed cells, which we named 3G, shedding of fine processes was observed over time and collected supernatants demonstrated elevated collagen levels compared to normal cell culture media. In contrast to chondrocytes, HDFs treated with CuHARS showed attenuated changes in morphology, and notably retained a prominent ability for continued proliferation. These results demonstrate that a copper-containing biohybrid material (CuHARS) can stably transform human chondrocytes with highly altered morphology, lower proliferation rates, and altered membrane dynamics compared to normal chondrocytes. In contrast, human dermal fibroblasts demonstrated attenuated changes in morphology, and retained an enhanced ability for proliferation.### Competing Interest StatementThe authors have declared no competing interest.
Green synthesis of nanomaterials endeavors to reduce the use of high energy methods with those that may include lower temperatures and pressures, use of natural products, and bottom-up self-assembly. Here we describe the generation of metal-organic biohybrids (MOBs) with nanoscale features synthesized at physiological (37°C) and room temperature (25°C). These MOBs utilized the naturally occurring amino acid dimer cystine as the biological component, and a series of metals, including copper, silver, and cobalt. The copper- and silver- based nanomaterials generated were distinct in size and shape. Copper formed elongated high-aspect ratio structures which we have named CuHARS. In contrast, the self-assembly of cystine and silver formed nanoparticles which we designate as AgCysNPs, and cobalt formed particles which we designate as CoMOBs. Both cobalt and silver could be combined with copper in the same reaction vessel to carry out green synthesis of different nanomaterials simultaneously. Post-synthesis the polarization of light by CuHARS provided one measure to distinguish the size and shape of different MOBs generated simultaneously.
Epilepsy treatment requires anti-seizure medical formulations; available medications have various painful side effects and penetrate the brain–blood barrier poorly. A promising method is the use of natural clay nanocontainers for drug delivery through this membrane barrier. Halloysites (Hly) are biocompatible, 50-nm diameter tubes with a positively charged, hollow inner lumen and negatively charged outer shell and are available naturally. These characteristics enable them to be versatile as drug loaded ‘nano-torpedoes’ effectively penetrating cell membranes. The endothelial cells are a major cell type in the blood–brain barrier that provides for the selective permeability separating the circulating blood and allowing only the passage of glucose, water, and amino acids, but not traditional drug formulations. Nanotubes encapsulating rhodamine isothiocyanate and ionomycin penetration through the rat-brain microvascular endothelial cells followed by a prolonged 24-h drug release was demonstrated. A model membrane was set up across 0.4-μm-pore polystyrene transwell supports covered by seeding endothelial and astrocyte cells to mimic the blood–brain barrier in vivo. This barrier demonstrated a dual permeation mechanism (inter-cell accumulation and through-passing) for loaded Hlys, exploiting the potential of this nanoclay in the trans-membrane delivery of drugs. Use of Hly nanotubes as drug carriers to penetrate the brain microvascular endothelial barrier and to deliver the payload displayed a new approach for the treatment of brain diseases such as epilepsy.
Although an abundance of drug candidates exists which are aimed at the remediation of central nervous system (CNS) disorders, the utility of some are severely limited by their inability to cross the blood brain barrier. Potential drug delivery systems such as the Angiopep family of peptides have shown modest potential; however, there is a need for novel drug delivery candidates that incorporate peptidomimetics to enhance the efficiency of transcytosis, specificity, and biocompatibility. Here, we report on the first in vitro cellular uptake and cytotoxicity study of a peptidomimetic, cationic peptide, L57. It binds to cluster 4 of the low-density lipoprotein receptor-related protein 1 (LRP1) receptor which is expressed in numerous cell types, such as brain endothelial cells. We used early-passage-number brain microvascular endothelial cells and astrocytes harvested from rat pup brains that highly express LRP1, to study the uptake of L57 versus Angiopep-7 (A7). Uptake of L57 and A7 showed a concentration-dependent increase, with L57 being taken up to a greater degree than A7 at the same concentration. Additionally, peptide uptake in LRP1-deficient PEA 10 cells had greatly reduced uptake. Furthermore, L57 demonstrated excellent cell viability versus A7, showing promise as a potential drug delivery vector for CNS therapeutics.
Copper high aspect ratio structures (CuHARS) and silver cystine nanoparticles (AgCysNPs) are two unique micro/nano particles under study here that show extensive anti-cancer effects on a glioma tumor cell line. These micro/nano particles have shown potent toxicity in the presence of inflammatory stimulus (combination of tumor necrosis factor, [TNF] and lipo-polysaccharide, LPS). CuHARS with a concentration of 20 μg/ml uniquely increased the catalytic generation of nitric oxide (NO), an important contributor in the immune system. This NO was generated in a cell culture tumor microenvironment (TME) in the presence of 25 µM S-nitrosothiol (cysteine-NO) and the inflammatory stimulus. CuHARS increased the NO production by 68.75% when compared to untreated glioma cells with CysNO and inflammatory stimulus. The production of NO was significantly higher under similar circumstances in the case of normal primary structural cells like brain microvascular endothelial cells (BMVECs). The production of NO by BMVECs went up by 181.25% compared to glioma cells. This significant increase in the NO concentration could have added up to tumorigenesis but the anti-cancer effect of CuHARS was prominent enough to lower down the viability of glioma cells by approximately 20% and increased the metabolism of structural cells, BMVECs by approximately 200%. The immunomodulatory effect of NO in the TME under these circumstances in the presence of the novel micro/nano material, CuHARS has risen up compared to the effect of inflammatory stimulus alone. The potency and specific nature of these materials toward tumor cells may make them suitable candidates for cancer treatment. Successive treatment of CuHARS to glioma cells also proved to be an effective approach considering the decrease in the total count of cells by 11.84 fold in case of three successive treatments compared to a single dose which only decreased the cell count by 2.45 fold showing the dose-dependent increasing toxicity toward glioma cells. AgCysNPs are another potent nanomaterial which also proved its significant toxic nature toward tumor cell lines as demonstrated here, but their immunomodulatory response is still unclear and needs to be explored further.
An intrinsic ion sensitivity exceeding the Nernst-Boltzmann limit and an sp(2)-hybridized carbon structure make graphene a promising channel material for realizing ion-sensitive field-effect transistors with a stable solid-liquid interface under biased conditions in buffered salt solutions. Here, we examine the performance of graphene field-effect transistors coated with ionselective membranes as a tool to selectively detect changes in concentrations of Ca2+, K+, and Na+ in individual salt solutions as well as in buffered Locke's solution. Both the shift in the Dirac point and transconductance could be measured as a function of ion concentration with repeatability exceeding 99.5% and reproducibility exceeding 98% over 60 days. However, an enhancement of selectivity, by about an order magnitude or more, was observed using transconductance as the indicator when compared to Dirac voltage, which is the only factor reported to date. Fabricating a hexagonal boron nitride multilayer between graphene and oxide further increased the ion sensitivity and selectivity of transconductance. These findings incite investigating ion sensitivity of transconductance in alternative architectures as well as urge the exploration of graphene transistor arrays for biomedical applications.
Glial cells play an important role in maintaining neuronal homeostasis and may thus influence excitability in epileptogenesis. These cells in the brain have glutamate (Glu) transporters, which remove this neurotransmitter from the extracellular space. Lack of negative (−) feedback makes local neuronal circuits more excitable and potentially contributing to epileptogenic phenomena. In this study, the role of glial cells in providing (−) feedback is shown through different models of brain cells in culture imaged for intracellular calcium concentration [(Ca2+)i]. Moreover, here we study the individual cells by putting them in categories. Neuronal networks with high and low (−) feedback were established by using anti-mitotics to deplete glial cells. Separate stimuli with very low subthreshold concentrations of Glu (250–750 nM) were added to cultures to test if the order of stimulations matter in regard to calcium dynamics outcomes. Additionally, KCl and ATP were used to stimulate glial cells. We found that for cultures high in (−) feedback, order of the stimulus was not important in predicting cellular responses and because of the complexity of networks in low (−) feedback cultures the order of stimulus matters. As an additional method for analysis, comparison of high (−) feedback cultures, and pure astrocytes was also considered. Glial cells in pure astrocyte cultures tend to be larger in size than glial cells in high (−) feedback cultures. The potential effect of (−) feedback at the blood brain barrier (BBB) was also considered for the inflammatory responses of nitric oxide (NO) production and [Ca2+]i regulation using brain microvascular endothelial cells (BMVECs). The inflammatory and calcium signaling pathways both indicate the negative feedback role of astrocytes, poised between the BBB and structures deeper within the brain, where neuronal synapses are homeostatically maintained by glial uptake of neurotransmitters.
Astrocytes, also known as astroglia, are important cells for the structural support of neurons as well as for biochemical balance in the central nervous system (CNS). In this study, the polymerization of dopamine (DA) to polydopamine (PDA) and its effect on astrocytes was investigated. The polymerization of DA, being directly proportional to the DA concentration, raises the prospect of detecting DA concentration from PDA optically using image-processing techniques. It was found here that DA, a naturally occurring neurotransmitter, significantly altered astrocyte cell number, morphology, and metabolism, compared to astrocytes in the absence of DA. Along with these effects on astrocytes, the polymerization of DA to PDA was tracked optically in the same cell culture wells. This polymerization process led to a unique methodology based on multivariate regression analysis that quantified the concentration of DA from optical images of astrocyte cell culture media. Therefore, this developed methodology, combined with conventional imaging equipment, could be used in place of high-end and expensive analytical chemistry instruments, such as spectrophotometry, mass spectrometry, and fluorescence techniques, for quantification of the concentration of DA after polymerization to PDA under in vitro and potentially in vivo conditions.
Neurological disorders that are characterized by unpredictable seizures affect people of all ages. We proposed the use of nanocarriers such as halloysite nanotubes to penetrate the blood-brain barrier and effectively deliver the payload over an extended time period. These 50-nm diameter tubes are a natural biocompatible nanomaterial available in large quantities. We proved a prolonged gradual drug delivery mechanism by the nanotube encapsulating rhodamine isothiocyanate and then ionomycin into brain microvascular endothelial cells (BMVECs). Through delayed diffusion, the nanotubes effectively delivered the drug to the primary BMVECs without killing them, by binding and penetration in time periods of 1 to 24 h.
The prodromal stages of some neurological diseases have a distinct electrical profile which can potentially be leveraged for early diagnosis, predicting disease recurrence, monitoring of disease progression, and better understanding of the disease pathology. Gliomas are tumors that originate from glial cells present in the brain and spinal cord. Healthy glial cells support normal neuronal function and play an important role in modulating the regular electrical activity of neurons. However, gliomas can disrupt the normal electrical dynamics of the brain. Though experimental and clinical studies suggest that glioma and injury to glial cells disrupt electrical dynamics of the brain, whether these disruptions are present during the earliest stages of glioma and glial injury are unclear. The primary aim of this study is to investigate the effect of early in vitro glial pathology (glioma and glial injury in specific) on neuronal electrical activity. In particular, we investigated the effect of glial pathology on neural synchronization: an important phenomenon that underlies several central neurophysiological processes (ScienceDirect, 2018 ). We used two in vitro disease samples: (a) a sample in which cortical cultures were treated with anti-mitotic agents that deplete glial cells and (b) a glioma sample in which healthy cortical cells were cultured with CRL-2303 (an aggressive glioma cell line). Healthy cortical culture samples were used as controls. Cultures were established over a glass dish embedded with microelectrodes that permits simultaneous measurement of extracellular electrical activity from multiple sites of the culture. We observed that healthy cortical cultures produce spontaneous and synchronized oscillations which were attenuated in the absence of glial cells. The presence of glioma was associated with the emergence of two types of “abnormal electrical activity” each with distinct amplitude and frequency profile. Our results indicate that even early stages of glioma and glial injury are associated with distinct changes in neuronal electrical activity.
The novel synthesis of metal-containing biohybrids using self-assembly methods at physiological temperatures (37 °C) was compared for copper and silver using the amino acid dimer cystine. Once assembled, the copper containing biohybrid is a stable, high-aspect ratio structure, which we call CuHARS. Using the same synthesis conditions, but replacing copper with silver, we have synthesized cystine-capped silver nanoparticles (AgCysNPs), which are shown here to form stable colloid solutions in contrast to the CuHARS, which settle out from a 1 mg/mL solution in 90 min. Both the copper and silver biohybrids, as synthesized, demonstrate very low agglomeration which we have applied for the purpose of applications with cell culture methods, namely, for testing as anti-cancer compounds. AgCysNPs (1000 ng/mL) demonstrated significant toxicity (only 6.8% viability) to glioma and neuroblastoma cells in vitro, with concentrations as low as 20 ng/mL causing some toxicity. In contrast, CuHARS required at least 5 μg/mL. For comparative purposes, silver sulfate at 100 ng/mL decreased viability by 52% and copper sulfate at 100 ng/mL only by 19.5% on glioma cells. Using these methods, the novel materials were tested here as metal-organic biohybrids (MOBs), and it is anticipated that the functionalization and dynamics of MOBs may result in building a foundation of new materials for cellular applications, including cell engineering of both normal and diseased cells and tissue constructs.
Bionanocomposite materials were developed from the assembly of polymer-coated copper-cystine high-aspect ratio structures (CuHARS) and cellulose fibers. The coating of the metal-organic materials with polyallylamine hydrochloride (PAH) allows their covalent linkage to TEMPO-oxidized cellulose by means of EDC/NHS. The resulting materials can be processed as films or macroporous foams by solvent casting and lyophilization, respectively. The films show good mechanical behavior with Young's moduli around 1.5 GPa as well as resistance in water, while the obtained foams show an open network of interconnected macropores with average diameters around 130 μm, depending on the concentration of the initial suspension, and compression modulus values around 450 kPa, similar to other reported freeze-dried nanocellulose-based aerogels. Based on these characteristics, the cellulose/PAH-CuHARS composites are promising for potential biomedical applications as implants or wound dressing materials. They have proved to be effective in the decomposition of low molecular weight S-nitrosothiols (RSNOs), similar to those existing in blood, releasing nitric oxide (NO). This effect is attributed to the presence of copper in the crystalline structure of the CuHARS building unit, which can be gradually released in the presence of redox species like ascorbic acid, typically found in blood. The resulting biomaterials can offer the interesting properties associated with NO, like antimicrobial activity as preliminary tests showed here with Escherichia coli and Staphylococcus epidermidis. In the presence of physiological concentration of RSNOs the amount of generated NO (around 360 nM) is not enough to show bactericidal effect on the studied bacteria, but it could provide other properties inherent to NO even at low concentration in the nM range like anti-inflammatory and anti-thrombotic effects. The cytotoxic effect recorded of the films on rat brain endothelial cells (BMVECs) is least significant and proves them to be friendly enough for further biological studies.