Improvement of Osteogenic Differentiation of Mouse Pre-Osteoblastic MC3T3-E1 Cells on Core-Shell Polylactic Acid/Chitosan Electrospun Scaffolds for Bone Defect Repair

Electrospun hybrid scaffolds composed of synthetic and natural polymers have gained increasing interest in tissue engineering applications over the last decade. In this work, scaffolds composed of polylactic acid electrospun fibers, either treated (P-PLA) or non-treated (PLA) with air-plasma, were coated with high molecular weight chitosan to create a core-shell microfibrous structure. The effective thickness control of the chitosan layer was confirmed by gravimetric, spectroscopic (FTIR-ATR) and morphological (SEM) investigations. The chitosan coating increased the fiber diameter of the microfibrous scaffolds while the tensile mechanical tests, conducted in dry and wet environments, showed a reinforcing action of the coating layer on the scaffolds, in particular when deposited on P-PLA samples. The stability of the Chi coating on both PLA and P-PLA substrates was confirmed by gravimetric analysis, while their mineralization capacity was evaluated though scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) after immersing the scaffolds in simulated body fluids (SBF) at 37 °C for 1 week. Sample biocompatibility was investigated through cell viability assay and SEM analysis on mouse pre-osteoblastic MC3T3-E1 cells grown on scaffolds at different times (1, 7, 14 and 21 days). Finally, Alizarin Red assay and qPCR analysis suggested that the combination of plasma treatment and chitosan coating on PLA electrospun scaffolds influences the osteoblastic differentiation of MC3T3-E1 cells, thus demonstrating the great potential of P-PLA/chitosan hybrid scaffolds for bone tissue engineering applications.

Collagen-Based Scaffolds for Chronic Skin Wound Treatment

Chronic wounds, commonly known as ulcers, represent a significant challenge to public health, impacting millions of individuals every year and imposing a significant financial burden on the global health system. Chronic wounds result from the interruption of the natural wound-healing process due to internal and/or external factors, resulting in slow or nonexistent recovery. Conventional medical approaches are often inadequate to deal with chronic wounds, necessitating the exploration of new methods to facilitate rapid and effective healing. In recent years, regenerative medicine and tissue engineering have emerged as promising avenues to encourage tissue regeneration. These approaches aim to achieve anatomical and functional restoration of the affected area through polymeric components, such as scaffolds or hydrogels. This review explores collagen-based biomaterials as potential therapeutic interventions for skin chronic wounds, specifically focusing on infective and diabetic ulcers. Hence, the different approaches described are classified on an action-mechanism basis. Understanding the issues preventing chronic wound healing and identifying effective therapeutic alternatives could indicate the best way to optimize therapeutic units and to promote more direct and efficient healing.

Nanoformulations based on collagenases loaded into halloysite/Veegum® clay minerals for potential pharmaceutical applications

The design and development of nanomaterials capable of penetrate cancer cells is fundamental when anticancer therapy is involved. The use of collagenase (Col) is useful since this enzyme can degrade collagen, mainly present in the tumor extracellular matrix. However, its use is often limited since collagenase suffers from inactivation and short half-life. Use of recombinant ultrapure collagenase or carrier systems for their delivery are among the strategies adopted to increase the enzyme stability. Herein, based on the more stability showed by recombinant enzymes and the possibility to use them in anticancer therapy, we propose a novel strategy to further increase their stability by using halloysite nanotubes (HNTs) as carrier. ColG and ColH were supramolecularly loaded onto HNTs and used as fillers for Veegum gels. The systems could be used for potential local administration of collagenases for solid tumor treatment. All techniques adopted for characterization showed that halloysite interacts with collagenases in different ways depending with the Col considered. Furthermore, the hydrogels showed a very slow release of the collagenases within 24 h. Finally, biological assays were performed by studying the digestion of a type-I collagen matrix highlighting that once released the Col still possessed some activity. Thus we developed carrier systems that could further increase the high recombinant collagenases stability, preventing their inactivation in future in vivo applications for potential local tumor treatment.

An Innovative Approach to Scalp Segmentation in Pediatric Brain Radiotherapy: An Atlas-Based Study

PURPOSE/OBJECTIVE(S)

This study aims to develop an atlas-based method for segmentation of the scalp in pediatric patients that received brain radiotherapy. The study focuses on the development of a model that utilizes CT scans of pediatric medulloblastoma (MB) patients who underwent craniospinal-irradiation (CSI) and a boost in the posterior cranial fossa (PCF).

MATERIALS/METHODS

A team of experts created the Alopecia_Hope (A_H) contouring protocol on the CT scan using the 2018 EPTN consensus-based atlas and by defining for the manual adjustments the anatomic bone landmarks to differentiate between the scalp and the facial and neck skin. Using RayStation version 12A-SP1, the system was running his latest available software version at the time of study. Automated scripts were created to identify bone tissue and skin as a subtraction volume between bone and body. The soft tissue CT window was then manually used to increase or decrease the thickness of the skin, following the landmarks outlined in the protocol. The entire head scalp was defined as WScalp (WS), and a duplicate and reduced version was also defined as PCFScalp (PCFS). We randomly chose 40 patients to create both WS and PCF atlas with RayStation and 8 patients were used as testers for both volumes, the patients with major bone changes after neurosurgery were excluded. The contouring time was recorded, the mean time was calculated, and the contouring results were analyzed by experts. Standard similarity metrics of 3D DICE similarity coefficient and mean distance to agreement (MDA) were calculated.

RESULTS

A total of 52 patients were selected for the study, with a median contouring time of 19 minutes using the guidelines, the A_H protocol and automatic scripting. Three patients were excluded. Of the 8 testers, including both volumes (WS and PCFS), the mean contouring time for the expert operator was 17.5 min. While the contouring undergone by the automatic atlas was 11 min and the mean time of the expert correction was 4.5 min. Considering the work done by the atlas is in background, this resulted in a time savings of 80% for the operator. Table 1 contains mean and one standard deviation data for the metric, both WS and PCFS tested.

CONCLUSION

Atlas-based self-segmentation and the Alopecia_Hope protocol offer a more efficient and accurate method to identify specific areas of the scalp that may be affected by post-radiotherapy hair loss. This study demonstrates the effectiveness and efficiency in reducing radiotherapy workload and improving accuracy, with possible future application in the prevention of permanent alopecia and in improving the quality of life of patients undergoing whole brain radiotherapy.

Recovery of Bioactive Compounds from Marine Organisms: Focus on the Future Perspectives for Pharmacological, Biomedical and Regenerative Medicine Applications of Marine Collagen

Marine environments cover more than 70% of the Earth's surface and are among the richest and most complex ecosystems. In terms of biodiversity, the ocean represents an important source, still not widely exploited, of bioactive products derived from species of bacteria, plants, and animals. However, global warming, in combination with multiple anthropogenic practices, represents a serious environmental problem that has led to an increase in gelatinous zooplankton, a phenomenon referred to as jellyfish bloom. In recent years, the idea of "sustainable development" has emerged as one of the essential elements of green-economy initiatives; therefore, the marine environment has been re-evaluated and considered an important biological resource. Several bioactive compounds of marine origin are being studied, and among these, marine collagen represents one of the most attractive bio-resources, given its use in various disciplines, such as clinical applications, cosmetics, the food sector, and many other industrial applications. This review aims to provide a current overview of marine collagen applications in the pharmacological and biomedical fields, regenerative medicine, and cell therapy.

High dose craniospinal irradiation as independent risk factor of permanent alopecia in childhood medulloblastoma survivors: cohort study and literature review

PURPOSE

Our aim was to determine the main risk factors related to the occurrence of permanent alopecia in childhood medulloblastoma (MB) survivors.

METHODS

We retrospectively analyzed the clinical features of all consecutive MB survivors treated at our institute. We divided the patients into 3 groups depending on the craniospinal irradiation (CSI) dose received and defined permanent alopecia first in terms of the skin region affected (whole scalp and nape region), then on the basis of the toxicity degree (G). Any relationship between permanent alopecia and other characteristics was investigated by a univariate and multivariate analysis and Odds ratio (OR) with confidence interval (CI) was reported.

RESULTS

We included 41 patients with a mean10-year follow-up. High dose CSI resulted as an independent factor leading to permanent hair loss in both groups: alopecia of the whole scalp (G1 p-value 0.030, G2 p-value 0.003) and of the nape region (G1 p-value 0.038, G2 p-value 0.006). The posterior cranial fossa (PCF) boost volume and dose were not significant factors at multivariate analysis neither in permanent hair loss of the whole scalp nor only in the nuchal region.

CONCLUSION

In pediatric patients with MB, the development of permanent alopecia seems to depend only on the CSI dose ≥ 36 Gy. Acute damage to the hair follicle is dose dependent, but in terms of late side effects, constant and homogeneous daily irradiation of a large volume may have a stronger effect than a higher but focal dose of radiotherapy.

Tolerance, Adaptation, and Cell Response Elicited by Micromonospora sp. Facing Tellurite Toxicity: A Biological and Physical-Chemical Characterization

The intense use of tellurium (Te) in industrial applications, along with the improper disposal of Te-derivatives, is causing their accumulation in the environment, where oxyanion tellurite (TeO32−) is the most soluble, bioavailable, and toxic Te-species. On the other hand, tellurium is a rare metalloid element whose natural supply will end shortly with possible economic and technological effects. Thus, Te-containing waste represents the source from which Te should be recycled and recovered. Among the explored strategies, the microbial TeO32− biotransformation into less toxic Te-species is the most appropriate concerning the circular economy. Actinomycetes are ideal candidates in environmental biotechnology. However, their exploration in TeO32− biotransformation is scarce due to limited knowledge regarding oxyanion microbial processing. Here, this gap was filled by investigating the cell tolerance, adaptation, and response to TeO32− of a Micromonospora strain isolated from a metal(loid)-rich environment. To this aim, an integrated biological, physical-chemical, and statistical approach combining physiological and biochemical assays with confocal or scanning electron (SEM) microscopy and Fourier-transform infrared spectroscopy in attenuated total reflectance mode (ATR-FTIR) was designed. Micromonospora cells exposed to TeO32− under different physiological states revealed a series of striking cell responses, such as cell morphology changes, extracellular polymeric substance production, cell membrane damages and modifications, oxidative stress burst, protein aggregation and phosphorylation, and superoxide dismutase induction. These results highlight this Micromonospora strain as an asset for biotechnological purposes.

Functionalized Poly(N-isopropylacrylamide)-Based Microgels in Tumor Targeting and Drug Delivery

Over the past several decades, the development of engineered small particles as targeted and drug delivery systems (TDDS) has received great attention thanks to the possibility to overcome the limitations of classical cancer chemotherapy, including targeting incapability, nonspecific action and, consequently, systemic toxicity. Thus, this research aims at using a novel design of Poly(N-isopropylacrylamide) p(NIPAM)-based microgels to specifically target cancer cells and avoid the healthy ones, which is expected to decrease or eliminate the side effects of chemotherapeutic drugs. Smart NIPAM-based microgels were functionalized with acrylic acid and coupled to folic acid (FA), targeting the folate receptors overexpressed by cancer cells and to the chemotherapeutic drug doxorubicin (Dox). The successful conjugation of FA and Dox was demonstrated by dynamic light scattering (DLS), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), UV-VIS analysis, and differential scanning calorimetry (DSC). Furthermore, viability assay performed on cancer and healthy breast cells, suggested the microgels’ biocompatibility and the cytotoxic effect of the conjugated drug. On the other hand, the specific tumor targeting of synthetized microgels was demonstrated by a co-cultured (healthy and cancer cells) assay monitored using confocal microscopy and flow cytometry. Results suggest successful targeting of cancer cells and drug release. These data support the use of pNIPAM-based microgels as good candidates as TDDS.

3D Collagen Hydrogel Promotes In Vitro Langerhans Islets Vascularization through ad-MVFs Angiogenic Activity

Adipose derived microvascular fragments (ad-MVFs) consist of effective vascularization units able to reassemble into efficient microvascular networks. Because of their content in stem cells and related angiogenic activity, ad-MVFs represent an interesting tool for applications in regenerative medicine. Here we show that gentle dissociation of rat adipose tissue provides a mixture of ad-MVFs with a length distribution ranging from 33–955 μm that are able to maintain their original morphology. The isolated units of ad-MVFs that resulted were able to activate transcriptional switching toward angiogenesis, forming tubes, branches, and entire capillary networks when cultured in 3D collagen type-I hydrogel. The proper involvement of metalloproteases (MMP2/MMP9) and serine proteases in basal lamina and extracellular matrix ECM degradation during the angiogenesis were concurrently assessed by the evaluation of alpha-smooth muscle actin (αSMA) expression. These results suggest that collagen type-I hydrogel provides an adequate 3D environment supporting the activation of the vascularization process. As a proof of concept, we exploited 3D collagen hydrogel for the setting of ad-MVF–islet of Langerhans coculture to improve the islets vascularization. Our results suggest potential employment of the proposed in vitro system for regenerative medicine applications, such as the improving of the islet of Langerhans engraftment before transplantation.

Neural Crest-Derived Chondrocytes Isolation for Tissue Engineering in Regenerative Medicine

Chondrocyte transplantation has been successfully tested and proposed as a clinical procedure aiming to repair articular cartilage defects. However, the isolation of chondrocytes and the optimization of the enzymatic digestion process, as well as their successful in vitro expansion, remain the main challenges in cartilage tissue engineering. In order to address these issues, we investigated the performance of recombinant collagenases in tissue dissociation assays with the aim of isolating chondrocytes from bovine nasal cartilage in order to establish the optimal enzyme blend to ensure the best outcomes of the overall procedure. We show, for the first time, that collagenase H activity alone is required for effective cartilage digestion, resulting in an improvement in the yield of viable cells. The extracted chondrocytes proved able to grow and activate differentiation/dedifferentiation programs, as assessed by morphological and gene expression analyses.

New European Clinical Trial Regulation: perception and expectations in Italy

Background

In July 2012, the European Commission formalized the proposal for a European Clinical Trial Regulation that should replace the European Clinical Trials Directive 2001/20/CE. The new Regulation 536/2014 entered into force in June 2014 and it was expected to be applied not earlier than May 2016. Indeed, at the time, all required central tools are not yet available and new forecasts indicate it will become effective at the end of 2018. The aims of the Regulation are the promotion of higher standards in patient's safety and increasing transparency in Clinical Trials, also by changing the application process.

Methods

An online survey was conducted among the Italian's Clinical Research Coordinators and Clinical Investigators to examine the perception and knowledge about the upcoming changes in Clinical Trials. A total of 190 Clinical Research Coordinators and 80 Clinical Investigators were surveyed.

Results

Clinicians are less aware of the content of the Regulation than Clinical Research Coordinators, who demonstrate an extensive expertise on the topic (84.4%), mainly reached through self-training. The majority of the Investigators (74%) believes that their site's facilities and staff already met all the requirements imposed by the Regulation while Clinical Research Coordinators are less optimistic: 65.2% of them believes that the site staff is not yet fully aware of changes associated to its implementation.

Conclusions

The general opinion of the interviewed is that the new Regulation will strongly affect the trial management regardless of their type and phase, and the fulfillment of the imposed requirements represents an opportunity that Italy should not miss to increase its attractiveness to the pharmaceutical market.

Abstract OT3-03-03: Challenges faced across borders to open European academic multicentre projects: The ET-FES program part of the ERA-Net TRANSCAN JTC 2011

Background

The activation of international non-profit clinical trials funded by the European Commission (EC) is challenging given the cross-borders regulations and the need to follow specific timelines according to EC rules. We report here the logistic procedures and challenges faced by 4 academic centres from 4 different countries from the European Union (EU) for the activation of such program in metastatic breast cancer (MBC).

Materials and Methods

The primary objective of the ET-FES program is to validate the use of a new radiotracer 18F Fluoroestradiol (FES), targeting estrogen receptors, as a tool to better predict endocrine responsiveness in MBC, with PET/CT. The trial is sponsored by EO Galliera (Genoa, Italy) and brings together Italy, Spain, France and Germany. In 10/2012, ET-FES was approved for funding from EC under the Seventh Framework Programme after the first ERA-NET TRANSCAN Joint Transnational Call (JTC) for Proposals (2011) on validation of new biomarkers for personalized cancer medicine.

Results

The official start of the program was set up on 06/2013 by the Italian Ministry of Health. Time to institutional review board and to competent authority (CA) approvals were 1.5 and 11, 2 and 5, 3 and 16, and 13 and 14+ months in Italy, France, Spain and Germany respectively. Overall, no blocking comment was raised by the ethical committees; only minor clinical and methodological issues were raised in Germany and Spain. Issues from CA were raised in all countries except France (12, 21 and 23 queries in Italy, Spain and Germany respectively), on quality aspects of 18F-FES investigational medicinal product dossier. At the sponsor level, time to final agreement signature with Advanced Accelerator Applications, the 18F-FES manufacturing company, required 13 months. First patient could be enrolled in Italy 14 and 22 months after ethical committee approval and after the official start of the ET-FES project respectively.

Conclusions

As of May 2016, of 310 patients expected, only 28 have been enrolled from Italy. From a regulatory viewpoint and acknowledging that 18F-FES does not have yet any marketing approval in the EU, the ET-FES program approval process was timely completed at the ethical committee level in Italy, France and Spain. Time to CA approval varied across countries and was timely achieved only in France, due to requirements varying from CA to CA, stressing the serious lack of harmonized procedures although intended by the 2001/20/EC directive. Regarding sponsor's responsibilities (i.e. Italy), the administrative procedures needed to activate this type of EU projects remain critical, appealing for more tolerant time span in order to satisfy all the legal aspects on contracts by public bodies, according to national rules and laws. One needs to be very conscious of these timelines when applying to EU/EC calls, especially when the time allowed for the conduction of research is limited (3 years here), unless jeopardizing the entire multicentre and multinational effort.

Citation Format: Brain E, Corradengo D, Oriana N, Piccardo A, Matteucci F, Cortes J, Harbeck N, Würstlein R, Piris A, Alberini J-L, Merlo DF, Degenhardt T, Turbiez I, Madar O, Monti M, Cesaro A, Rivitti E, Rollandi GA, Iacozzi M, Campazzi E, Campora S, Camporese D, Gennari A. Challenges faced across borders to open European academic multicentre projects: The ET-FES program part of the ERA-Net TRANSCAN JTC 2011 [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT3-03-03.

Multi-Functional Nanogels for Tumor Targeting and Redox-Sensitive Drug and siRNA Delivery

(1) Background: A new family of nanosystems able to discern between normal and tumor cells and to release a therapeutic agent in controlled way were synthetized by e-beam irradiation. This technique permits to obtain biocompatible, sterile, carboxyl-functionalized polyvinylpyrrolidone (PVP-co-acrylic acid) nanogels (NGs); (2) Methods: Here, we performed a targeting strategy based on the recognition of over-expressed proteins on tumor cells, like the folate receptor. The selective targeting was demonstrated by co-culture studies and flow cytometry analysis, using folate conjugated NGs. Moreover, nanoparticles were conjugated to a chemotherapeutic drug or to a pro-apoptotic siRNA through a glutathione sensitive spacer, in order to obtain a controlled release mechanism, specific for cancer cells. The drug efficiency was tested on tumor and healthy cells by flow cytometric analysis, confocal and epifluorescence microscopy and cytotoxicity assay; the siRNA effect was investigated by RNAi experiment; (3) Results: The data obtained showed that the use of NGs permits a faster cargo release in cancer cells, in response to high cytosolic glutathione level, also improving their efficacy; (4) Conclusion: The possibility of releasing biological molecules in a controlled way and to recognize a specific tumor target allows overcoming the typical limits of the classic cancer therapy.

Polyaminoacid–doxorubicin prodrug micelles as highly selective therapeutics for targeted cancer therapy

An amphiphilic copolymer carrying high-dose doxorubicin (21% on a weight basis), PHEA–EDA–P,C–Doxo, was prepared by coupling doxorubicin with a biocompatible polyaminoacid through a pH-sensitive spacer.

Self-organized environment-sensitive inulin–doxorubicin conjugate with a selective cytotoxic effect towards cancer cells

An inulin-based copolymer bearing high dose doxorubicin (18.45 % w/w), INU-EDA-P,C-DOXO, was prepared by coupling doxorubicin with inulin though citraconylamide bridge used as pH sensitive spacer. Its smart and selective anticancer effect was proved.

Abstract P2-05-01: A Comparative Study of 18F-Fluoride PET/CT and Whole-Body High Resolution CT (HRCT) for the Detection of Bone Metastases in Patients with Advanced Breast Cancer

Background: Bone scintigraphy (BS) have been shown to be of value in detecting bone metastases several months before conventional radiography, whereas computed tomography (HRCT) and magnetic resonance imaging (MRI) can reveal more metastases in the spine than conventional BS. 18F-Fluoride PET has been shown to be more accurate than BS for the detection bone lesions in different malignancies and has been suggested as an alternative to BS. Recent studies have shown that integrated 18F-Fluoride-PET/CT is both sensitive and specific for detection of lytic and sclerotic lesions and is superior to 18F-Fluoride PET. The aim of our study is to evaluate the diagnostic accuracy of 18F-Fluoride-PET/CT in comparison to HRCT for the detection of bone metastases in breast cancer patients.

Material and methods: The study involved 39 patients with breast cancer with known bone metastases or at high risk for its presence. All patients presented indications for skeletal surveys. Imaging was performed on an integrated PET/CT system. All PET scans were acquired in 2D mode and were reconstructed using an iterative reconstruction algorithm; diagnostic HRCT data of PET/CT were acquired for detecting bone lesions and were used for attenuation correction. PET acquisition started 60 min after intravenous injection of 370-550 MBq 18F-labelled NaF and included 10-12 bed positions.

The interpretation of PET/CT and High resolution CT studies was made as a consensus reading of two nuclear medicine physicians and a radiologist who had access to clinical, as well as previous radiological imaging information. 12 months follow-up based on previous and/or following imaging studies was considered the gold standard. Results: Overall 671 bone lesions were detected in our analysis including both PET/CT and CT results. Of these lesions 530 malignant, 32 equivocal and 109 benign were classified by consensus reading. 18F-Fluoride PET/CT detected 491 bone metastases, 114 (23%) of which without any clear morphological changes on CT. HRCT detected 416 bone metastases, 39 (9.3%) of which without any 18F-fluoride uptake. The overall sensitivity and specificity was 90% and 91% for 18F-Fluoride-PET/CT and 79 and 93% for HRCT, respectively. In a patients based analysis both 18F-Fluoride-PET/CT and HRCT identified the same number of patients with bone metastases (27 of 39).

Conclusions: Our data show a high agreement (71% of lesions and 100% of the patients) between 18F-Fluoride-PET/CT and HRCT for bone metastases detection. However integrated analysis of 18F-Fluoride-PET/HRCT has the best diagnostic option to evaluate bone involvement in breast cancer, and 18F-Fluoride-PET/CT seems to have the highest sensitivity. Follow-up is ongoing to assess the prognostic/predictive value of 18F-Fluoride-PET/CT.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-05-01.