25 July 2022
Marketed dosage forms fail to deliver anti-tubercular drugs directly to the lungs in pulmonary Tuberculosis (TB). Therefore, nanomediated isoniazid (INH)-loaded dry powder for inhalation (Nano-DPI) was developed for macrophage-targeted delivery in TB. Mannosylated chitosan (MC) and hyaluronic acid (HA) with an affinity for the surface mannose and CD44 receptors of macrophages were used in conjugation to prepare hybrid nanosuspension by ionic gelation method using cross-linker, sodium tri-polyphosphate (TPP) followed by freeze-drying to obtain a dry powder composed of nanoparticles (INH-MC/HA NPs). Nanoformulations were evaluated for aerodynamic characteristics, cytotoxicity, hemocompatibility, macrophage phenotype analysis, and immune regulation. Cellular uptake imaging was also conducted to evaluate the uptake of NPs. The nanopowders did not pose any significant toxicity to the cells, along with good compatibility with red blood cells (RBCs). The pro-inflammatory costimulatory markers were upregulated, demonstrating the activation of T-cell response. Moreover, the NPs did not show any tolerogenic effect on the macrophages. Furthermore, confocal imaging exhibited the translocation of NPs in the cells. Altogether, the findings present that nano-DPI was found to be a promising vehicle for targeting macrophages.
23 October 2021
Tuberculosis (TB) is an infectious disease that causes a great number of deaths in the world (1.5 million people per year). This disease is currently treated by administering high doses of various oral anti-TB drugs for prolonged periods (up to 2 years). While this regimen is normally effective when taken as prescribed, many people with TB experience difficulties in complying with their medication schedule. Furthermore, the oral administration of standard anti-TB drugs causes severe side effects and widespread resistances. Recently, we proposed an original platform for pulmonary TB treatment consisting of mannitol microspheres (Ma MS) containing iron (III) trimesate metal-organic framework (MOF) MIL-100 nanoparticles (NPs). In the present work, we loaded this system with the first-line anti-TB drug isoniazid (INH) and evaluated both the viability and safety of the drug vehicle components, as well as the cell internalization of the formulation in alveolar A549 cells. Results show that INH-loaded MOF (INH@MIL-100) NPs were efficiently microencapsulated in Ma MS, which displayed suitable aerodynamic characteristics for pulmonary administration and non-toxicity. MIL-100 and INH@MIL-100 NPs were efficiently internalized by A549 cells, mainly localized in the cytoplasm. In conclusion, the proposed micro-nanosystem is a good candidate for the pulmonary administration of anti-TB drugs.
25 June 2021
Pollen grains are natural microcapsules comprised of the biopolymer sporopollenin. The uniformity and special tridimensional architecture of these sporopollenin structures confer them attractive properties such as high resistance and improved bioadhesion. However, natural pollen can be a source of allergens, hindering its biomedical applicability. Several methods have been developed to remove internal components and allergenic compounds, usually involving long and laborious processes, which often cannot be extended to other pollen types. In this work, we propose an abridged protocol to produce stable and pristine hollow pollen microcapsules, together with a complete physicochemical and morphological characterization of the intermediate and final products. The optimized procedure has been validated for different pollen samples, also producing sporopollenin microcapsules from Matricaria species for the first time. Pollen microcapsules obtained through this protocol presented low protein content (4.4%), preserved ornamented morphology with a nanoporous surface, and low product density (0.14 g/cm3). These features make them interesting candidates from a pharmaceutical perspective due to the versatility of this biomaterial as a drug delivery platform.
https://doi.org/10.3390/polym13132094
02 March 2021
Chitosan-based nanosystems have been described as interesting tools for antigen delivery and for enhancing the immunogenicity of nasally administered vaccines. As a possible vaccine delivery method, the chemical conjugation of chitosan nanocapsules with the Streptococcus pneumoniae cell membrane protein PsaA (pneumococcal surface adhesin A) is suggested here. The antigen PsaA, common to all pneumococcus serotypes, is expected to improve its uptake by immune cells and to activate specific T cells, generating an adaptive immune response against pneumococcus. With this aim, chitosan nanocapsules with thiol-maleimide conjugation between the polymer (chitosan) and the antigen (PsaA) were designed to enable the surface presentation of PsaA for immune cell recognition. Spherical-shaped particles, with a size of 266 ± 32 nm, positive charge of +30 ± 1 mV, and good stability profiles in simulated nasal fluids (up to 24 h) were achieved. PsaA association rates were three times higher compared with nanocapsules without covalent polymer-protein conjugation. Cytotoxicity studies in cell culture media showed non-toxic effect under 150 µg/mL concentration of nanocapsules, and subsequent studies on the maturation of immature dendritic cells in the presence of antigen-conjugated nanocapsules displayed peripheral blood mononuclear cell activation and lymphocyte differentiation after their presentation by dendritic cells. Secretion of TNFα following exposure to nanocapsules and the ability of nanocapsules to activate CD4 and CD8 T lymphocytes had also been studied
DOI: 10.1007/s13346-021-00928-3
20 February 2021
Fundamental studies performed during the last decades have shown that cell fate is much more plastic than previously considered, and technologies for its manipulation are a keystone for many new tissue regeneration therapies. Transcription factors (TFs) are DNA-binding proteins that control gene expression, and they have critical roles in the control of cell fate and other cellular behavior. TF-based therapies have much medical potential, but their use as drugs depends on the development of suitable delivery technologies that can help them reach their action site inside of the cells. TFs can be used either as proteins or encoded in polynucleotides. When used in protein form, many TFs require to be associated to a cell-penetrating peptide or another transduction domain. As polynucleotides, they can be delivered either by viral carriers or by non-viral systems such as polyplexes and lipoplexes. TF-based therapies have extensively shown their potential to solve many tissue-engineering problems, including bone, cartilage and cardiac regeneration. Yet, their use has expanded beyond regenerative medicine to other prominent disease areas such as cancer therapy and immunomodulation. This review summarizes some of the delivery options for effective TF-based therapies and their current main applications.
15 May 2020
Gene delivery within hydrogel matrices can potentially direct mesenchymal stem cells (MSCs) towards a chondrogenic fate to promote regeneration of cartilage. Here, we investigated whether the mechanical properties of the hydrogel containing the gene delivery systems could enhance transfection and chon- drogenic programming of primary human bone marrow-derived MSCs. We developed collagen-I-alginate interpenetrating polymer network hydrogels with tunable stiffness and adhesion properties. The hydro- gels were activated with nanocomplexed SOX9 polynucleotides to direct chondrogenic differentiation of MSCs. MSCs transfected within the hydrogels showed higher expression of chondrogenic markers com- pared to MSCs transfected in 2D prior to encapsulation. The nanocomplex uptake and resulting expression of transfected SOX9 were jointly enhanced by increased stiffness and cell-adhesion ligand density in the hydrogels. Further, transfection of SOX9 effectively induced MSCs chondrogenesis and reduced markers of hypertrophy compared to control matrices. These findings highlight the importance of matrix stiffness and adhesion as design parameters in gene-activated matrices for regenerative medicine.
25 March 2020
Polyphosphazenes (PPZs) are a relatively new family of polymers based on a nitrogen-phosphorous backbone where organicside groups can be grafted. The synthetic route to PPZs is highly versatile such that it is possible to add many different functionalitiesthat change completely the physicochemical and biological properties of the polymers. For instance, PPZs can be designed with a varietyof organic side groups that render these materials biodegradable and highly biocompatible. Based on these positive features, PPZs havebeen explored for many biomedical applications including the design of numerous advanced drug delivery systems. In this area, PPZshave been particularly investigated as materials for the formulation of biopharmaceuticals of high added value. These include protein-and polynucleotide-based medicines, applications where PPZ carriers have obtained very positive results in preclinical models. A furtherarea of major interest for PPZs has been vaccination, where these materials have obtained excellent results in vivo as polymer adjuvantsand have advanced to clinical evaluation.
10 June 2020
Nanocapsules (NCs) have become one of the most researched nanostructured drug delivery systems due to their advantageous properties and versatility. NCs can enhance the bioavailabiliy of hydrophobic drugs by impoving their solubility and permeability. Also, they can protect these active pharmaceutical agents (APIs) from the physiological environment with preventing e.g. the enzymatic degradation. NCs can be used for many administration routes: e.g. oral, dermal, nasal and ocular formulations are exisiting in liquid and solid forms. The nose is one of the most interesting alternative drug administration route, because local, systemic and direct central nervous system (CNS) delivery can be achived; this could be utilized in the therapy of CNS diseases. Therefore, the goal of this study was to design, prepare and investigate a novel, lamotrigin containing NC formulation for nasal administration. The determination of micrometric parameters (particle size, polydispersity index, surface charge), in vitro (drug loading capacity, release and permeability investigations) and in vivo characterization of the formulations were performed in the study. The results indicate that the formulation could be a promising alternative of lamotrigine (LAM) as the NCs were around 305 nm size with high encapsulation efficiency (58.44%). Moreover, the LAM showed rapid and high release from the NCs in vitro and considerable penetration to the brain tissues was observed during the in vivo study.
10 January 2020
This chapter is part of the book Therapeutic Dressings and Wound Healing Applications, this book takes a clinical and scientific approach to wound healing, and includes recent case studies to highlight key points and areas of improvement. It is divided into two key sections that include insight into the biochemical basis of wounds, as well as techniques and recent advancements. Chapters include information on: (I) Debridement and disinfection properties of wound dressing; (II) Biofilms, silver nanoparticles, and honey dressings; (III) Clinical perspectives for treating diabetic wounds; (IV) Treating mixed infections; (V) Wound healing and tissue regeneration treatments; (VI) Gene based therapy, 3D bioprinting and freeze-dried wafers.
Chapter 10. Gene Therapy for the Treatment of Chronic Wounds
In wound healing, gene therapy strategies have the largest potential as new treatments for refractory chronic wounds. This potential of gene therapy stems from its capacity to regulate genes that reverse the key hallmarks driving chronic wound formation: inflammation, reduced angiogenesis, and impaired re‐epithelization. Indeed, the most important strategies followed with gene therapy have been signalling supplementation and the inhibition of critical pathways that are dysregulated in chronic wounds. Gene therapies in wound healing can be delivered either by a systemic administration route or, more commonly, by local administration. The chapter briefly discusses a specific delivery platform of particular interest in tissue regeneration and wound healing referred to as a gene‐activated matrix. The results from the clinical trials analysed to date have confirmed the safety of gene therapy strategies in chronic wound management but present an uncertain landscape regarding efficacy.
16 June 2020
The oral route is one of the most attractive modalities of drug delivery, providing easy administration and great patient compliance. However, enzymatic degradation and physiological barriers in the gastrointestinal tract are still unsolved obstacles for many drugs. The physico-chemical characteristics of biopharmaceuticals and the resulting low stability and poor penetration capacity across biological barriers represent current challenges that need to be overcome in oral delivery. The use of polyaminoacids and polypeptides, including cell-penetrating peptides as delivery carriers is an attractive strategy to improve the oral bioavailability of therapeutics. These biopolymers are positioned as potential biomaterials due to their low toxicity and their capacity to enhance the stability of biomolecules while increasing their transport through biological barriers.
In this review, we present an update of the current approaches and strategies carried out in the design of nanosystems and penetration-enhancing oral delivery strategies based on polyaminoacids.
Polyaminoacids and polypeptides are functional and versatile biomaterials which have received significant attention for the design of oral drug delivery platforms. Even though only a few prototypes have yet entered clinical trials, a number of promising strategies can be found in advanced preclinical investigation for the delivery of biopharmaceuticals.
31 March 2020
Gene-activated matrices (GAMs) encoding pivotal transcription factors (TFs) represent a powerful tool to direct stem cell specification for tissue engineering applications. However, current TF-based GAMs activated with pDNA, are challenged by their low transfection efficiency and delayed transgene expression. Here, we report a GAM technology activated with mRNAs encoding TFs SOX9 (cartilage) and MYOD (muscle). We find that these mRNA-GAMs induce a higher and faster TF expression compared to pDNA-GAMs, especially in the case of RNase resistant mRNA sequences. This potent TF expression was translated into a high synthesis of cartilage- and muscle-specific markers, and ultimately, into successful tissue specification in vitro. Additionally, we show that the expression of tissue-specific markers can be further modulated by altering the properties of the mRNA-GAM environment. These results highlight the value of this GAM technology for priming cell lineage specification, a key centerpiece for future tissue engineering devices.
6 March 2020
This chapter belongs to the book entitled Biomaterials for Cancer Therapeutics: Evolution and innovation, adetailed overview of the nature of cancer cells and biomaterials used for the detection, treatment, and prevention of a variety of cancer types.
Chapter 13. Suppression of cancer stem cells
The current evidence confirms that tumor initiation and recurrence is generally governed by a subpopulation of tumor cells with stem-like signatures: cancer stem cells (CSCs). This population needs to be considered a pivotal target for tumor treatment, since it combines drug resistance and the capacity to restore tumors even from a few cells. Several drugs and biopharmaceuticals are being tested for their capacity to suppress CSCs based on their capacity to interfere with key-signaling pathways required to maintain this privileged and aggressive phenotype. However, these molecules have often poor biopharmaceutical properties, significant side effects, difficulties to reach their target site, and short half-lives. These limitations have motivated the integration of these therapeutic molecules in advanced drug delivery systems for improved stability, intratumoral penetration, and efficacy. We envisage that such delivery technologies will have important roles in new promising strategies based on combined drug therapies for disrupting the CSC niche and achieving cancer remission.
Preparation of sophisticated delivery systems for nanomedicine applications generally involve multistep procedures using organic solvents. In this study, we have developed a simple self-assembling
process to prepare docetaxel-loaded hyaluronic acid (HA) nanocapsules by using a self-emulsifcation
process without the need of organic solvents, heat or high shear forces. These nanocapsules, which
comprise an oily core and a shell consisting of an assembly of surfactants and hydrophobically modifed
HA, have a mean size of 130nm, a zeta potential of −20 mV, and exhibit high docetaxel encapsulation
efciency. The nanocapsules exhibited an adequate stability in plasma. Furthermore, in vitro studies
performed using A549 lung cancer cells, showed efective intracellular delivery of docetaxel. On the
other hand, blank nanocapsules showed very low cytotoxicity. Overall, these results highlight the
potential of self-emulsifying HA nanocapsules for intracellular drug delivery.
Purpose: Gasdermin B (GSDMB) overexpression/amplification occurs in about 60% of HER2 breast cancers, where it
promotes cell migration, resistance to anti-HER2 therapies,
and poor clinical outcome. Thus, we tackle GSDMB cytoplasmic overexpression as a new therapeutic target in HER2
breast cancers.
Experimental Design: We have developed a new targeted
nanomedicine based on hyaluronic acid-biocompatible
nanocapsules, which allow the intracellular delivery of a
specific anti-GSDMB antibody into HER2 breast cancer cells
both in vitro and in vivo.
Results: Using different models of HER2 breast cancer
cells, we show that anti-GSDMB antibody loaded to nanocapsules has significant and specific effects on GSDMBoverexpressing cancer cells' behavior in ways such as
(i) lowering the in vitro cell migration induced by GSDMB;
(ii) enhancing the sensitivity to trastuzumab; (iii) reducing
tumor growth by increasing apoptotic rate in orthotopic
breast cancer xenografts; and (iv) diminishing lung metastasis in MDA-MB-231-HER2 cells in vivo. Moreover, at a
mechanistic level, we have shown that AbGB increases
GSDMB binding to sulfatides and consequently decreases
migratory cell behavior and may upregulate the potential
intrinsic procell death activity of GSDMB.
Conclusions: Our findings portray the first evidence of the
effectiveness and specificity of an antibody-based nanomedicine that targets an intracellular oncoprotein. We have proved
that intracellular-delivered anti-GSDMB reduces diverse protumor GSDMB functions (migration, metastasis, and resistance to therapy) in an efficient and specific way, thus providing a new targeted therapeutic strategy in aggressive HER2
cancers with poor prognosis.
Microporousfilms are structures with attractive features as high porosity and high intrinsic surface area.Unfortunately, most biocompatible materials useful for the preparation of such microporousfilms are sub-optimal for drug delivery due to poor processability and/or drug encapsulation properties. Silkfibroin (SF) is abiocompatible protein with good drug release properties and suitable characteristics for pharmaceutical pro-cessing. Dextran sulphate (DSS) is an anionic polysaccharide with the capacity to interact and stabilize manyproteins. In the current study, we evaluate the effect of DSS on the physical properties of SF/DSS blendfilms,how it affects the molecular and microscopic structure of the system and its capacity for providing controlledrelease of a model protein. Using this system, micro- and nanostructuredfilms could be prepared through agreen, water-only process. It was found that DSS acted both as a modifier of SF secondary structure and as afunctional porogen, where the size of nano- and micropores varied with the blending ratios. High ratios showedhigher swelling, porosity and crystallinity, resulting in modified protein release kinetics, as compared to pure SFfilms. Considering both their mild preparation method and their physical and pharmaceutical properties, SF/DSSfilms stand out as ideal systems for sustained protein delivery applications.
Myeloid-Derived Suppressor Cells (MDSCs), immunosuppressive cells that promote tumor growth, represent an
attractive target in cancer immunotherapy. However, the clinical success of this strategy is limited by the lack of
efficient drug delivery vehicles targeting this cell compartment. The objective of this work was to develop a
delivery carrier, multilayer polymer nanocapsules, with the capacity to co-encapsulate two types of immunomodulatory drugs, a chemokine and an RNAi sequence, aimed at reverting MDSC-mediated immunosuppression. The chemokine CCL2, intended to attract monocyte-macrophage MDSCs, was encapsulated
within the L2 inverse micellar aqueous domains of the lipid core of these nanocapsules. On the other hand, two
different RNAi sequences that modulate the CCAAT/enhancer-binding protein beta (C/EBPβ) pathway, shC/
EBPβ and miR 142-3p, were successfully associated to their polymer shell. These RNAi sequences were covered
by subsequent layers of polyarginine and hyaluronic acid, thereby creating multi-layered assemblies that protected them and facilitated their targeted delivery. The in vitro studies performed in primary MDSCs cultures
showed the capacity of miR 142-3p-loaded nanocapsules to reduce the highly immunosuppressive monocytemacrophage subset. Additionally, the encapsulation of CCL2 within the nanocapsules induced a potent monocyte-macrophage chemoattraction that could be used to direct the therapy to these cell subsets. Finally, in vitro
and in vivo studies showed the capacity of shC/EBPβ-loaded nanocapsules to downregulate C/EBPβ levels in
MDSCs and to reduce monocyte differentiation into tumor-associated macrophages in an MCA-203 fibrosarcoma
mice model. In conclusion, the multilayer polymer nanocapsules described here are efficient vehicles for the codelivery of proteins and RNA, and are potential candidates as nanomedicines for the modulation of MDSCs.
This chapter is part of the book Advances in Drug Delivery Strategies for Microbial Healthcare Products, which has been assembled with the hope of being an authoritative, comprehensive, conceptually sound and highly informative compilation of recent advances describing the concepts of bioengineering in the field of microbiology. It comprises of seven chapters written by eminent authors in their respective fields. Topics included deal with the significant advancement of microbial technology with emphasis on drug delivery strategies for healthcare products, vaccine delivery.
Chapter 1. Advances in Drug Delivery Strategies for Microbial Healthcare Products
Biomacromolecules produced by microorganisms have been employed in healthcare ever since ancient times as part of fermented products or natural remedies, but from the discovery of penicillin in 1928 by Alexander Fleming, it is impossible to conceive medicine without microbial products. In addition to antibiotics, microorganisms produce secondary metabolites currently employed as antiinflammatory, immunosuppressant, and antitumoral drugs, among others. As with any other well-established drugs, undesirable side effects may occur with these compounds due to excessive systemic drug concentrations, and their pharmacological activity can be lost by the development of resistance in the target cells. Besides, many microbial drugs have intrinsic physicochemical properties that limit their application in healthcare such as low aqueous solubility, low bioavailability, acute toxicity, and fast systemic and pre-systemic degradation. Here we review the critical aspects of innovative strategies for microbial products of high interest for academia and healthcare industry. In order to improve some of the current drug limitations, researchers have explored multiple advanced formulation approaches based on disruptive technologies. By means of new biomaterials and nanotechnology, it is possible to maximize the possibilities for functionalization and interfacing with the biological environment, a characteristic that leads to unique properties as drug delivery carriers. These approaches have resulted in improved pharmacological effects and pharmaceutical characteristics as compared to classical formulations, representing the dawn of a new era in microbial healthcare products.
Lack of improvement in the treatment options of several types of cancer can largely be attributed to the presence of a subpopulation of cancer cells with stem cell signatures and to the tumoral niche that supports and protects these cells. This review analyses the main strategies that specifically modulate or suppress cancer stem cells (CSCs) and the tumoral niche (TN), focusing on the role of biomaterials (i.e. implants, nanomedicines, etc.) in these therapies. In the case of CSCs, we discuss differentiation therapies and the disruption of critical cellular signaling networks. For the TN, we analyze diverse strategies to modulate tumor hypervascularization and hypoxia, tumor extracellular matrix, and the inflammatory and tumor immunosuppressive environment. Due to their capacity to control drug disposition and integrate diverse functionalities, biomaterial-based therapies can provide important benefits in these strategies. We illustrate this by providing case studies where biomaterial-based therapies either show CSC suppression and TN disruption or improved delivery of major modulators of these features. Finally, we discuss the future of these technologies in the framework of these emerging therapeutic concepts.