Core cross-linked polymeric micelles (CCPMs) are designed to improve the therapeutic profile of hydrophobic drugs, reduce or completely avoid protein corona formation, and offer prolonged... Show moreCore cross-linked polymeric micelles (CCPMs) are designed to improve the therapeutic profile of hydrophobic drugs, reduce or completely avoid protein corona formation, and offer prolonged circulation times, a prerequisite for passive or active targeting. In this study, we tuned the CCPM stability by using bifunctional or trifunctional cross-linkers and varying the cross-linkable polymer block length. For CCPMs, amphiphilic thiol-reactive polypept(o)ides of polysarcosine-block-poly(S-ethylsulfonyl-l-cysteine) [pSar-b-pCys(SO2Et)] were employed. While the pCys(SO2Et) chain lengths varied from Xn = 17 to 30, bivalent (derivatives of dihydrolipoic acid) and trivalent (sarcosine/cysteine pentapeptide) cross-linkers have been applied. Asymmetrical flow field-flow fraction (AF4) displayed the absence of aggregates in human plasma, yet for non-cross-linked PM and CCPMs cross-linked with dihydrolipoic acid at [pCys(SO2Et)]17, increasing the cross-linking density or the pCys(SO2Et) chain lengths led to stable CCPMs. Interestingly, circulation time and biodistribution in mice of non-cross-linked and bivalently cross-linked CCPMs are comparable, while the trivalent peptide cross-linkers enhance the circulation half-life from 11 to 19 h. Show less
Vught, L. van; Que, I.; Luyten, G.P.M.; Beenakker, J.W.M. 2022
Purpose: To assess the effect of ocular anatomy and intraocular lens (IOL) design on negative dysphotopsia (ND).Setting: Department of Ophthalmology, Leiden University Medical Center, Leiden, the... Show morePurpose: To assess the effect of ocular anatomy and intraocular lens (IOL) design on negative dysphotopsia (ND).Setting: Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands.Design: Ray-tracing study based on clinical data.Methods: Ray-tracing simulations were performed to assess the effect of anatomical differences and differences in IOL design on the peripheral retinal illumination. To that end, eye models that incorporate clinically measured anatomical differences between eyes of patients with ND and eyes of pseudophakic controls were created. The anatomical differences included pupil size, pupil centration, and iris tilt. The simulations were performed with different IOL designs, including a simple biconvex IOL design and a more complex clinical IOL design with a convex-concave anterior surface. Both IOL designs were analyzed using a clear edge and a frosted edge. As ND is generally considered to be caused by a discontinuity in peripheral retinal illumination, this illumination profile was determined for each eye model and the severity of the discontinuity was compared between eye models.Results: The peripheral retinal illumination consistently showed a more severe discontinuity in illumination with ND-specific anatomy. This difference was the least pronounced, 8%, with the frosted edge clinical IOL and the most pronounced, 18%, with the clear edge biconvex IOL.Conclusions: These results show that small differences in the ocular anatomy or IOL design affect the peripheral retinal illumination. Therewith, they can increase the severity of ND by up to 18%. Copyright (c) 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of ASCRS and ESCRS Show less
Upconversion nanoparticles (UCNPs) represent a group of NPs that can convert near-infrared (NIR) light into ultraviolet and visible light, thus possess deep tissue penetration power with less... Show moreUpconversion nanoparticles (UCNPs) represent a group of NPs that can convert near-infrared (NIR) light into ultraviolet and visible light, thus possess deep tissue penetration power with less background fluorescence noise interference, and do not induce damage to biological tissues. Due to their unique optical properties and possibility for surface modification, UCNPs can be exploited for concomitant antigen delivery into dendritic cells (DCs) and monitoring by molecular imaging. In this study, we focus on the development of a nano-delivery platform targeting DCs for immunotherapy and simultaneous imaging. OVA 254-267 (OVA24) peptide antigen, harboring a CD8 T cell epitope, and Pam3CysSerLys4 (Pam3CSK4) adjuvant were chemically linked to the surface of UCNPs by amide condensation to stimulate DC maturation and antigen presentation. The OVA24-Pam3CSK4-UCNPs were thoroughly characterized and showed a homogeneous morphology and surface electronegativity, which promoted a good dispersion of the NPs. In vitro experiments demonstrated that OVA24-Pam3CSK4-UCNPs induced a strong immune response, including DC maturation, T cell activation, and proliferation, as well as interferon gamma (IFN-gamma) production. In vivo, highly sensitive upconversion luminescence (UCL) imaging of OVA24-Pam3CSK4-UCNPs allowed tracking of UCNPs from the periphery to lymph nodes. In summary, OVA24-Pam3CSK4-UCNPs represent an effective tool for DC-based immunotherapy. Show less
The intra-articular administration of drugs has attracted great interest in recent decades for the treatment of osteoarthritis. The use of modified drugs has also attracted interest in recent years... Show moreThe intra-articular administration of drugs has attracted great interest in recent decades for the treatment of osteoarthritis. The use of modified drugs has also attracted interest in recent years because their intra-articular administration has demonstrated encouraging results. The objective of this work was to prepare injectable-thermosensitive hydrogels for the intra-articular administration of Etanercept (ETA), an inhibitor of tumor necrosis factor-alpha. Hydrogels were prepared from the physical mixture of chitosan and Pluronic F127 with beta-glycerolphosphate (BGP). Adding beta-glycerolphosphate to the system reduced the gelation time and also modified the morphology of the resulting material. In vitro studies were carried out to determine the cytocompatibility of the prepared hydrogels for the human chondrocyte line C28/I2. The in vitro release study showed that the incorporation of BGP into the system markedly modified the release of ETA. In the in vivo studies, it was verified that the hydrogels remained inside the implantation site in the joint until the end of the study. Furthermore, ETA was highly concentrated in the blood of the study mice 48 h after the loaded material was injected. Histological investigation of osteoarthritic knees showed that the material promotes cartilage recovery in osteoarthritic mice. The results demonstrate the potential of ETA-loaded injectable hydrogels for the localized treatment of joints. Show less
Cartilage diseases currently affect a high percentage of the world's population. Almost all of these diseases, such as osteoarthritis (OA), cause inflammation of this soft tissue. However, this... Show moreCartilage diseases currently affect a high percentage of the world's population. Almost all of these diseases, such as osteoarthritis (OA), cause inflammation of this soft tissue. However, this could be controlled with biomaterials that act as an anti-inflammatory delivery system, capable of dosing these drugs over time in a specific area. The objective of this study was to incorporate etanercept (ETA) into porous three-layer scaffolds to decrease the inflammatory process in this soft tissue. ETA is a blocker of pro-inflammatory cytokines, such as tumour necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6). For this reason, the scaffold was built based on natural polymers, including chitosan and type I collagen. The scaffold was grafted next to subchondral bone using hydroxyapatite as filler. One of the biomaterials obtained was also crosslinked to compare its mechanical properties with the non-treated one. Both samples' physicochemical properties were studied with SEM, micro-CT and photoacoustic imaging, and their rheological properties were also compared. The cell viability and proliferation of the human chondrocyte C28/I2 cell line were studied in vitro. An in vitro and in vivo controlled release study was evaluated in both specimens. The ETA anti-inflammatory effect was also studied by in vitro TNF-alpha and IL-6 production. The crosslinked and non-treated scaffolds had rheological properties suitable for this application. They were non-cytotoxic and favoured the in vitro growth of chondrocytes. The in vitro and in vivo ETA release showed desirable results for a drug delivery system. The TNF-alpha and IL-6 production assay showed that this drug was effective as an anti-inflammatory agent. In an in vivo OA mice model, safranin-O and fast green staining was carried out. The OA cartilage tissue improved when the scaffold with ETA was grafted in the damaged area. These results demonstrate that this type of biomaterial has high potential for clinical applications in tissue engineering and as a controlled drug delivery system in OA articular cartilage. Show less
Collaborative therapy is regarded as an effective approach in increasing the therapeutic efficacy of cancer. In this work, we have proposed and validated the concept of upconversion lumienscence... Show moreCollaborative therapy is regarded as an effective approach in increasing the therapeutic efficacy of cancer. In this work, we have proposed and validated the concept of upconversion lumienscence image guided synergy of photodynamic therapy (PDT) and radiotherapy (RT) for deep cancer, via a specially designed nanoplatform integrating near infrared (NIR) light activated luminescence upconversion and X-ray induced scintillation. Upon NIR light irradiation, the nanoplatform emits highly monochromatic red light solely for imaging the targeted cancer cells without triggering therapy; however, when the irradiation turns to a low dose of X-rays, scintillation will occur which induces effectively the PDT destroying the cancer cells together with X-ray induced RT. The novel theranostic nanoplatform is constructed in such a way that the interactions between the upconversion core and the outmost scintillating shell are blocked effectively by an inert layer between them. This structural design not only enables a nearly perfect excitation energy delivery (similar to 100% at a spectral overlapping wavelength of similar to 540 nm) from the outermost scintellating layer to the surface-anchored photosensitizers and so a maximum yield of radical oxygen species, but also achieves a strong NIR induced upconversion luminescence for imaging. Since PDT and RT attack different parts of a cancer cell, this synergy is more effective in destroying cancer than a single therapy, resulting in the reduction of the X-ray irradiation dosage. As a proof of principle, the theranostic effect is validated by in vitro and in vivo experiments, exhibiting the great potential of this sort of nanoplatform in deep cancer treatment. Show less
In cancer treatment, nanomedicines may be employed in an attempt to improve the tumor localization of antineoplastic drugs e.g. immunotherapeutic agents either through passive or active targeting,... Show moreIn cancer treatment, nanomedicines may be employed in an attempt to improve the tumor localization of antineoplastic drugs e.g. immunotherapeutic agents either through passive or active targeting, thereby potentially enhancing therapeutic effect and reducing undesired off-target effects. However, a large number of administrated nanocarriers often fail to reach the tumor area. In the present study, we show that photodynamic therapy (PDT) enhances the tumor accumulation of systemically administered lipid-PEG layer coated poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP). Intravital microscopy and histological analysis of the tumor area reveal that the tumor vasculature was disrupted after PDT, disturbing blood flow and coinciding with entrapment of nanocarriers in the tumor area. We observed that the nanoparticles accumulating after treatment do not confine to specific locations within the tumor, but rather localize to various cells present throughout the tumor area. Finally, we show by flow cytometry that NP accumulation occurred mostly in immune cells of the myeloid lineage present in the tumor microenvironment (TME) as well as in tumor cells, albeit to a lower extent. These data expose opportunities for combination treatments of clinical PDT with NP-based immunotherapy to modulate the TME and improve antitumor immune responses. Show less
Schomann, T.; Iljas, J.D.; Que, I.; Li, Y.D.; Suidgeest, E.; Cruz, L.J.; ... ; Mezzanotte, L. 2020
Traumatic brain injury (TBI) is a devastating event for which current therapies are limited. Stem cell transplantation may lead to recovery of function via different mechanisms, such as cell... Show moreTraumatic brain injury (TBI) is a devastating event for which current therapies are limited. Stem cell transplantation may lead to recovery of function via different mechanisms, such as cell replacement through differentiation, stimulation of angiogenesis and support to the microenvironment. Adult hair follicle bulge-derived stem cells (HFBSCs) possess neuronal differentiation capacity, are easy to harvest and are relatively immune-privileged, which makes them potential candidates for autologous stem cell-based therapy. In this study, we apply in vivo multimodal, optical and magnetic resonance imaging techniques to investigate the behavior of mouse HFBSCs in a mouse model of TBI. HFBSCs expressed Luc2 and copGFP and were examined for their differentiation capacity in vitro. Subsequently, transduced HFBSCs, preloaded with ferumoxytol, were transplanted next to the TBI lesion (cortical region) in nude mice, 2 days after injury. Brains were fixed for immunohistochemistry 58 days after transplantation. Luc2- and copGFP-expressing, ferumoxytol-loaded HFBSCs showed adequate neuronal differentiation potential in vitro. Bioluminescence of the lesioned brain revealed survival of HFBSCs and magnetic resonance imaging identified their localization in the area of transplantation. Immunohistochemistry showed that transplanted cells stained for nestin and neurofilament protein (NF-Pan). Cells also expressed laminin and fibronectin but extracellular matrix masses were not detected. After 58 days, ferumoxytol could be detected in HFBSCs in brain tissue sections. These results show that HFBSCs are able to survive after brain transplantation and suggest that cells may undergo differentiation towards a neuronal cell lineage, which supports their potential use for cell-based therapy for TBI. Show less
Feng, Y.S.; Chen, H.R.; Wu, Y.N.; Que, I.; Tamburini, F.; Baldazzi, F.; ... ; Zhang, H. 2020
Side effect is one of the main factors affecting the success of cancer therapies in clinic. Patients treated with photodynamic therapy (PDT) suffer mainly from the phototoxicity due to the... Show moreSide effect is one of the main factors affecting the success of cancer therapies in clinic. Patients treated with photodynamic therapy (PDT) suffer mainly from the phototoxicity due to the relatively long time blood circulation of the tumor enrichment and they have also to be protected from background light for days after the treatment. Here we introduce a new design of nanophotosensitizers in which the luminescence upconversion nanoparticles loaded with photosensitizers are self-assembled into a nanoball with the aid of a specific pH-sensitive polymer layer containing overloaded photosensitizers and quenching molecules. This design makes the therapy function "off/on" possible, i.e. only imaging during the circulation of the nanoballs ascribing to the near-infrared (NIR) photon upconversion of the nanoballs and the pH-sensitive shell. Activation of PDT solely occurs once the nanoballs are taken up by the cancer cells due to the acidic microenvironment. This design prevents effectively the photodamage of the photosensitizers during enrichment and targeting process of tumor, as validated in vitro and in vivo, which enables imaging-guided PDT treatment of deep-seated tumor in a much more relax and comfortable way for patients. This patient-friendly nanomaterial construction strategy can also be extended to other therapies. Show less
Various tissue engineering systems for cartilage repair have been designed and tested over the past two decades, leading to the development of many promising cartilage grafts. However, no one has... Show moreVarious tissue engineering systems for cartilage repair have been designed and tested over the past two decades, leading to the development of many promising cartilage grafts. However, no one has yet succeeded in devising an optimal system to restore damaged articular cartilage. Here, the design, assembly, and biological testing of a porous, chitosan/collagen-based scaffold as an implant to repair damaged articular cartilage is reported. Its gradient composition and trilayer structure mimic variations in natural cartilage tissue. One of its layers includes hydroxyapatite, a bioactive component that facilitates the integration of growing tissue on local bone in the target area after scaffold implantation. The scaffold was evaluated for surface morphology; rheological performance (storage, loss, complex, and time-relaxation moduli at 1 kHz); physiological stability; in vitro activity and cytotoxicity (on a human chondrocyte C28 cell line); and in vivo performance (tissue growth and biodegradability), in a murine model of osteoarthritis. The scaffold was shown to be mechanically resistant and noncytotoxic, favored tissue growth in vivo, and remained stable for 35 days postimplantation in mice. These encouraging results highlight the potential of this porous chitosan/collagen scaffold for clinical applications in cartilage tissue engineering. Show less
Aim Thoracic aortic aneurysms are a life-threatening condition often diagnosed too late. To discover novel robust biomarkers, we aimed to better understand the molecular mechanisms underlying... Show moreAim Thoracic aortic aneurysms are a life-threatening condition often diagnosed too late. To discover novel robust biomarkers, we aimed to better understand the molecular mechanisms underlying aneurysm formation.Methods and results In Fibulin-4(R/R) mice, the extracellular matrix protein Fibulin-4 is 4-fold reduced, resulting in progressive ascending aneurysm formation and early death around 3 months of age. We performed proteomics and genomics studies on Fibulin-4(R/R) mouse aortas. Intriguingly, we observed alterations in mitochondrial protein composition in Fibulin-4(R/R) aortas. Consistently, functional studies in Fibulin-4(R/R) vascular smooth muscle cells (VSMCs) revealed lower oxygen consumption rates, but increased acidification rates. Yet, mitochondria in Fibulin-4(R/R) VSMCs showed no aberrant cytoplasmic localization. We found similar reduced mitochondrial respiration in Tgfbr-1(M318R/+) VSMCs, a mouse model for Loeys-Dietz syndrome (LDS). Interestingly, also human fibroblasts from Marfan (FBN1) and LDS (TGFBR2 and SMAD3) patients showed lower oxygen consumption. While individual mitochondrial Complexes I-V activities were unaltered in Fibulin-4(R/R) heart and muscle, these tissues showed similar decreased oxygen consumption. Furthermore, aortas of aneurysmal Fibulin-4(R/R) mice displayed increased reactive oxygen species (ROS) levels. Consistent with these findings, gene expression analyses revealed dysregulation of metabolic pathways. Accordingly, blood ketone levels of Fibulin-4(R/R) mice were reduced and liver fatty acids were decreased, while liver glycogen was increased, indicating dysregulated metabolism at the organismal level. As predicted by gene expression analysis, the activity of PGC1 alpha, a key regulator between mitochondrial function and organismal metabolism, was downregulated in Fibulin-4(R/R) VSMCs. Increased TGF beta reduced PGC1 alpha levels, indicating involvement of TGF beta signalling in PGC1 alpha regulation. Activation of PGC1 alpha restored the decreased oxygen consumption in Fibulin-4(R/R) VSMCs and improved their reduced growth potential, emphasizing the importance of this key regulator.Conclusion Our data indicate altered mitochondrial function and metabolic dysregulation, leading to increased ROS levels and altered energy production, as a novel mechanism, which may contribute to thoracic aortic aneurysm formation. Show less
Pluijm, I. van der; Burger, J.; Heijningen, P.M. van; Ijpma, A.; Vliet, N. van; Milanese, C.; ... ; Essers, J. 2018
