Barbara Richichi

The therapeutic monoclonal antibody bevacizumab is typically purified using protein A affinity chromatography, a highly effective but costly method. Affinity-based precipitation for antibody purification is a lower-cost approach. In this work, a precipitation protocol was developed for bevacizumab purification using a branched peptide (Ac-PHQGQHIG-Ahx₃)₂-K-Ahx₃-PHQGQHIG-NH₂, which contains the epitope PHQGQHIG that is responsible for interacting with bevacizumab. The peptide was synthesised by a microwave-assisted solid-phase peptide method, employing LiCl as an additive to prevent aggregation and ensure high purity and yield. Three molecules of 6-aminohexanoic acid were introduced between each epitope branch as spacer arms to promote the formation of cyclic complexes. Bevacizumab purification from cell-free culture broth was achieved through a fractional precipitation process. First, a negative precipitation step using (NH₄)₂SO₄ 1.18 M was performed to remove contaminants. Afterwards, 5 moles of peptide per mol of bevacizumab was added to the supernatant, together with additional (NH₄)₂SO₄, to reach a final concentration of 1.20 M. Under these conditions, bevacizumab was recovered in the precipitate with 98% purity and a yield of 73%. In addition to being recyclable, the peptide’s relatively low production cost could enable the development of a single-use purification process, which would be particularly advantageous for biopharmaceutical manufacturing.

The therapeutic monoclonal antibody bevacizumab is typically purified using Protein-A affinity chromatography, a highly effective but costly method. As a lower-cost alternative, affinity-based precipitation has been described to purify antibodies. Therefore, in this work, a precipitation protocol was developed for bevacizumab purification using the branched peptide (Ac-PHQGQHIG-Ahx₃)2-K-Ahx₃-PHQGQHIG-NH₂, which contains the epitope PHQGQHIG responsible for interaction with bevacizumab. The peptide was synthesised by microwave-assisted solid-phase peptide synthesis employing LiCl as an additive to prevent aggregation and ensure high purity and yield. Three molecules of 6-aminohexanoic acid were introduced between each epitope branch as spacer arms to promote the formation of cyclic complexes. Bevacizumab purification from the cell-free culture broth was achieved through a fractional precipitation process. First, a negative precipitation step using (NH₄)₂SO₄ 1.18 M was performed to remove contaminants. Afterwards, 5 moles of peptide per mol of bevacizumab were added to the supernatant, together with additional (NH₄)₂SO₄ to reach a final concentration of 1.20 M. Under these conditions, bevacizumab was recovered in the precipitate with 98% purity and a yield of 73%. In addition to being recyclable, the peptide´s relative low production cost may enable the development of a single-use purification process, which would be particularly advantageous for biopharmaceutical manufacturing.

Introduction: Bevacizumab, applied in cancer treatment, binds vascular endothelial growth factor (VEGF) inhibiting blood vessels growth, avoiding tumours expansion

The unique physicochemical properties of gold nanoparticles (GNPs) have made them versatile tools for biomedical applications, such as imaging, therapy, and drug delivery. The surface modification of GNPs with polymers or biomolecules can enhance their colloidal stability and facilitate internalization into cells. However, the efficient and biocompatible delivery to the central nervous system remains a major challenge, as many existing nanocarriers show poor capacity to cross the blood-brain barrier. We developed a method to coat GNPs with linear polyethyleneimine (GNP@PEI) through a chemical reduction bottom-up approach, in which linear PEI hydrochloride acts simultaneously as a reducing and stabilizing agent of colloidal dispersion. This strategy yielded monodisperse spherical GNP@PEI nanoparticles with an average diameter of 50 nm. The physicochemical profile, biocompatibility, and capacity for neural uptake of this potentially brain-targeted nanoplatform were then evaluated. GNP@PEI nanoparticles exhibited high biocompatibility in several primary neural cultures and cell lines, with cellular uptake showing clear cell-type-dependent differences. In vivo studies carried out in a murine model demonstrated that after the intranasal or intraperitoneal administrations of GNP@PEI nanoparticles, detectable levels of gold were found in several organs, including the brain. Collectively, these findings highlight the potential of GNP@PEI as a promising nanoplatform for brain-targeted delivery and for advancing the development of therapeutic strategies for neurological disorders.

Activation of microglia and resulting neuroinflammation are central processes that significantly contribute to neurodegenerative disease progression. Treatments capable of attenuating neuroinflammation are therefore an urgent medical need. Vitis vinifera L., cultivated since ancient times for its fruits, is known for its antioxidant and anti-inflammatory activities. However, polyphenols, the main bioactive molecules in V. vinifera extracts, exhibit considerable variability due to numerous hard-to-control factors, which complicates the production of standardized extracts with consistent biological activity. To address this issue, plant cell culture biotechnology was used to produce a highly standardized V. vinifera phytocomplex (VP), and its anti-neuroinflammatory profile was investigated in LPS-stimulated microglial cells, an in vitro model of neuroinflammation. VP reduced the LPS-induced pro-inflammatory phenotype, improved cell viability and cell number, attenuated NF-κB activation and ERK1/2 phosphorylation, and increased SIRT1 levels. To overcome VP’s poor water solubility, water-soluble cellulose nanocrystal (CNC)-based formulations were developed and tested. VP-CNC formulations markedly reduced the BV2 pro-inflammatory phenotype and increased cell viability under both basal and LPS-stimulated conditions. The nanoformulations also decreased pERK1/2 levels and increased SIRT1 expression, exhibiting biological activities comparable to VP alone. V. vinifera phytocomplex derived from plant cell cultures represents an innovative and standardized product with promising anti-neuroinflammatory properties.

We report here the use of Tris-BODIPY-OH as a scaffold for the multivalent display of sugar heads. A chloroacetyl thioether ligation reaction easily yields mannosylated BODIPYs, named Man₉-BODIPY and (Man-TEG)₉-BODIPY, which display nine mannose residues. Regardless of the linker length, both glycoBODIPYs provide an arrangement of mannose heads that allows for proper recognition by the carbohydrate binding domain of concanavalin A (ConA). Moreover, the interactions of Man₉-BODIPY with relevant human lectins, i.e. dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) and langerin, were further investigated. The approach proposed is versatile and paves the way for the development of multivalent and fluorescent glyco-BODIPY probes useful to interrogate carbohydrate–lectin interactions in different biological contexts.

Activation of microglia and resulting neuroinflammation are central processes that significantly contribute to neurodegenerative disease progression. Treatments capable of attenuating neuroinflammation are therefore an urgent medical need. Vitis vinifera L., cultivated since ancient times for its fruits, is known for its antioxidant and anti-inflammatory activities. However, polyphenols, the main bioactive molecules in V. vinifera extracts, vary considerably due to numerous hard-to-control factors, making it difficult to obtain standardized extracts with consistent biological activity. To address this issue, plant cell culture biotechnology was used to produce a highly standardized V. vinifera phytocomplex (VP), and its anti-neuroinflammatory profile was investigated in LPS-stimulated microglial cells, an in vitro model of neuroinflammation. VP reduced the LPS-induced pro-inflammatory phenotype, improved cell viability and cell number, attenuated NF-κB activation and ERK1/2 phosphorylation, and increased SIRT1 levels. To overcome VP’s poor water solubility, water-soluble, nanocellulose-based formulations containing cellulose nanocrystal (CNC) were developed and tested. VP-CNC formulations markedly reduced the BV2 pro-inflammatory phenotype and increased cell viability under both basal and LPS-stimulated conditions. The nanoformulations also decreased pERK1/2 levels and increased SIRT1 expression, exhibiting biological activities comparable to VP alone. V. vinifera phytocomplex derived from plant cell cultures represents an innovative and standardized product with promising antineuroinflammatory properties.

The conjugation of fluorescent probes to tumor-targeting molecules represents a promising strategy for the development of precision cancer bioimaging and treatment. Among the different tumor-targeting strategies, the use of d-glucose residues, which exploit the high energy demand of cancer cells, can enable recognition by a broad spectrum of tumors, thus overcoming limitations related to cancer heterogeneity. In this study, we combined the distinctive optical properties of BODIPY-based probes with the known tumor-targeting abilities of d-glucose. We report on the characterization of a glucosylated BODIPY, named Glc-BODIPY, and its ability to target different cancer cell types in both in vitro and in vivo models.

In mammals, every cell is covered by a sugar coat called the “glycocalyx”, a meshwork created by sugar modifications of cell surface proteins and lipids. Essentially all cell membrane proteins and lipids contain oligosaccharide clusters known as “glycan motifs” that confer distinct functional properties on these respective glycoproteins or glycolipids. These motifs are generated by glycosyltransferases that assemble the component monosaccharides in a stereospecific and regiospecific fashion. Glycocalyx motifs bearing l-fucose in α(1→3) linkage to N-acetyl-glucosamine are found on a highly restricted subset of membrane glycoproteins and glycolipids, and changes in α(1→3)-fucosylation levels impact a wide range of physiologic and pathologic processes. Within this biological framework, we herein review the pivotal role of α(1→3)-fucosylation in cell biology and then comprehensively review the evolving chemical strategies to custom-modify α(1→3)-fucosylation of the glycocalyx to achieve highly specific control of human cell surface fucosylated glycan motifs. These efforts serve as a prime example of how the fine control of cell surface fucosylation can enable the generation of glycan-based precision therapeutics, driving forward the field of “translational glycobiology”.

We report here on a straightforward methodology to synthesize a new water-soluble fluorescent probe Tris-BODIPY-OH 1 that contains three pH-independent hydrophilic arms. This probe has been prepared by exploiting a synthetic strategy that includes as a key step the combination of a Cu-(I)-catalyzed azide-alkyne cycloaddition (CuAAC) and a Sonogashira cross-coupling in a sequential one-pot approach. Tris-BODIPY-OH 1 provides a significant advancement in the field by expanding the BODIPY toolbox with a biocompatible water-soluble probe, which can be used to specifically label and assess the function of the endoplasmic reticulum.