vNARs as Neutralizing Intracellular Therapeutic Agents: Glioblastoma as a Target.

Glioblastoma is the most prevalent and fatal form of primary brain tumors. New targeted therapeutic strategies for this type of tumor are imperative given the dire prognosis for glioblastoma patients and the poor results of current multimodal therapy. Previously reported drawbacks of antibody-based therapeutics include the inability to translocate across the blood-brain barrier and reach intracellular targets due to their molecular weight. These disadvantages translate into poor target neutralization and cancer maintenance. Unlike conventional antibodies, vNARs can permeate tissues and recognize conformational or cryptic epitopes due to their stability, CDR3 amino acid sequence, and smaller molecular weight. Thus, vNARs represent a potential antibody format to use as intrabodies or soluble immunocarriers. This review comprehensively summarizes key intracellular pathways in glioblastoma cells that induce proliferation, progression, and cancer survival to determine a new potential targeted glioblastoma therapy based on previously reported vNARs. The results seek to support the next application of vNARs as single-domain antibody drug-conjugated therapies, which could overcome the disadvantages of conventional monoclonal antibodies and provide an innovative approach for glioblastoma treatment.

Radical Scavenging, Hemocompatibility, and Antibacterial Activity against MDR Acinetobacter baumannii in Alginate-Based Aerogels Containing Lipoic Acid-Capped Silver Nanoparticles.

Retaining the hemocompatibility, supporting cell growth, and exhibiting anti-inflammatory and antioxidant properties, while having antimicrobial activity, particularly against multidrug-resistant bacteria (MDR), remain a challenge when designing aerogels for biomedical applications. Here, we report that our synthesized alginate-based aerogels containing either 7.5 or 11.25 µg of lipoic acid-capped silver nanoparticles (AgNPs) showed improved hemocompatibility properties while retaining their antimicrobial effect against MDR Acinetobacter baumannii and the reference strain Escherichia coli, relative to a commercial dressing and polymyxin B, used as a reference. The differences in terms of the microstructure and nature of the silver, used as the bioactive agent, between our synthesized aerogels and the commercial dressing used as a reference allowed us to improve several biological properties in our aerogels with respect to the reference commercial material. Our aerogels showed significantly higher antioxidant capacity, in terms of nmol of Trolox equivalent antioxidant capacity per mg of aerogel, than the commercial dressing. All our synthesized aerogels showed anti-inflammatory activity, expressed as nmol of indomethacin equivalent anti-inflammatory activity per mg of aerogel, while this property was not found in the commercial dressing material. Finally, our aerogels were highly hemocompatible (less than 1% hemolysis ratio); however, the commercial material showed a 20% hemolysis rate. Therefore, our alginate-based aerogels with lipoic acid-capped AgNPs hold promise for biomedical applications.

Embedded Living HER2+ Cells in a 3D Gelatin-Alginate Hydrogel as an In Vitro Model for Immunotherapy Delivery for Breast Cancer.

Epidermal growth factor receptor 2 (HER2) is the second target molecule most commonly used in breast cancer treatment. Both recurrence and metastasis are still deadly for HER2+ breast cancer patients. Hydrogels can be an option for developing three-dimensional (3D) cell culture systems that resemble tumor features better than monolayer cultures and could be used for preclinical screening for new biotherapeutics. Biopolymers (gelatin and alginate) were used to develop a hydrogel capable of encapsulating living HER2+ breast cancer cells BT-474/GFP. The hydrogel was physicochemically characterized, and the viability of embedded cells was evaluated. The hydrogel developed had suitable physical properties, with swelling of 38% of its original mass at 20 h capacity and pore sizes between 20 and 125 µm that allowed cells to maintain their morphology in a 3D environment, in addition to being biocompatible and preserving 90% of cell viability at 10 days. Furthermore, encapsulated BT-474/GFP cells maintained HER2 expression that could be detected by the Trastuzumab-fluorescent antibody, so this hydrogel could be used to evaluate new HER2-targeted therapies.

Potential Therapeutic Applications of Synthetic Conotoxin s-cal14.2b, Derived from Californiconus californicus, for Treating Type 2 Diabetes.

The FDA's approval of peptide drugs such as Ziconotide or Exendin for pain relief and diabetes treatment, respectively, enhanced the interest to explore novel conotoxins from Conus species venom. In general, conotoxins can be used in pathologies where voltage-gated channels, membrane receptors, or ligands alter normal physiological functions, as in metabolic diseases such as Type 2 diabetes. In this study, the synthetic cal14.2b (s-cal14.2b) from the unusual Californiconus californicus demonstrated bioactivity on NIT-1 insulinoma cell lines stimulating insulin secretion detecting by high performance liquid chromatography (HPLC). Accordingly, s-cal14.2b increased the CaV1.2/1.3 channel-current by 35 ± 4% with a recovery τ of 10.3 ± 4 s in primary cell culture of rat pancreatic ß-cells. The in vivo results indicated a similar effect of insulin secretion on mice in the glucose tolerance curve model by reducing the glucose from 500 mg/dL to 106 mg/dL in 60 min, compared to the negative control of 325 mg/dL at the same time. The PET-SCAN with radiolabeling 99mTc-s-cal14.2b demonstrated biodistribution and accumulation in rat pancreas with complete depuration in 24 h. These findings show the potential therapeutic use of s-cal14.2b in endocrinal pathologies such as early stages of Type 2 Diabetes where the pancreas's capability to produce insulin is still effective.

3D Cell Culture Models in COVID-19 Times: A Review of 3D Technologies to Understand and Accelerate Therapeutic Drug Discovery.

In the last decades, emerging viruses have become a worldwide concern. The fast and extensive spread of the disease caused by SARS-CoV-2 (COVID-19) has impacted the economy and human activity worldwide, highlighting the human vulnerability to infectious diseases and the need to develop and optimize technologies to tackle them. The three-dimensional (3D) cell culture models emulate major tissue characteristics such as the in vivo virus-host interactions. These systems may help to generate a quick response to confront new viruses, establish a reliable evaluation of the pathophysiology, and contribute to therapeutic drug evaluation in pandemic situations such as the one that humanity is living through today. This review describes different types of 3D cell culture models, such as spheroids, scaffolds, organoids, and organs-on-a-chip, that are used in virus research, including those used to understand the new severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2).

Improvement of the wound healing properties of hydrogels with N-acetylcysteine through their modification with methacrylate-containing polymers.

Hydrogels with antioxidant activity have shown to significantly improve the standard of care, because they promote efficient wound healing, i.e. regeneration. N-Acetylcysteine (NAC) is an antioxidant amino acid derivative that promotes complete tissue restoration. However, NAC has anticoagulant properties that may also hinder blood coagulation, which is crucial for hydrogels for wound healing applications. To take advantage of the regenerative activity of NAC while avoiding hampering the hemostasis stage during wound healing, we modified gelatin-NAC with the methacrylate-containing polymers 2-hydroxyethyl methacrylate (H) and poly(ethylene glycol) methyl ether methacrylate (P) to produce Gel-HP-NAC. These hydrogels clotted more blood and faster than Gel and Gel-NAC hydrogels, while maintaining fluid absorption properties adequate to promote wound healing. Similarly, there were more viable human skin fibroblasts after 10 days cultured in Gel-HP-NAC compared with Gel and Gel-NAC. A mouse full-thickness skin wound model demonstrated that Gel-HP-NAC hydrogels improved the wound healing process as compared to the untreated group as proved by the increased wound closure rates and re-epithelialization. Histology of the biopsied tissues indicated more organized collagen deposits on the wounds treated with either Gel-HP-NAC or Gel-NAC than untreated wounds. Our results show that modification of NAC-containing hydrogels through methacrylate-containing polymers improved their wound healing properties, including blood-clotting, and demonstrate the potential of Gel-HP-NAC hydrogels for wound treatment and tissue regeneration.

iPSC for modeling neurodegenerative disorders.

Neurodegenerative disorders such as Parkinson's and Alzheimer's disease, are fundamental health concerns all around the world. The development of novel treatments and new techniques to address these disorders, are being actively studied by researchers and medical personnel. In the present review we will discuss the application of induced Pluripotent Stem Cells (iPSCs) for cell-therapy replacement and disease modelling. The aim of iPSCs is to restore the functionality of the damaged tissue by replacing the impaired cells with competitive ones. To achieve this objective, iPSCs can be properly differentiated into virtually any cell fate and can be strongly translated into human health via in vitro and in vivo disease modeling for the development of new therapies, the discovery of biomarkers for several disorders, the elaboration and testing of new drugs as novel treatments, and as a tool for personalized medicine.

Effect of starch on the mechanical and in vitro properties of collagen-hydroxyapatite sponges for applications in dentistry.

This study sought to improve the mechanical and blood-absorbing properties of collagen sponges, while keeping them compressible, by incorporating blended hydroxyapatite (HA)-starch. Results were compared with CollaPlug(®) (pure collagen). The elastic modulus increased from 1.5±0.2kPa for CollaPlug(®) to 49±8kPa for sponges with composition 1:4:10 (collagen:HA:starch, by weight). The modified microstructure and surface area provided by the starch granules on the sponges improved cell viability. Sponges with composition 1:4:10 maintained their blood-clotting capability with almost no change from 5 to 15min after contact with blood, while CollaPlug(®) diminished to about half its capacity to absorb blood and form clots. Incorporation of HA-starch into the sponges with composition of 1:4:10, increased the elastic modulus of the collagen-HA sponges, making them more structurally robust. The viability of cells and the blood-clotting capability increased with starch incorporation.