Oligo-metastatic neoPlasms from the gastro-intestinal tract: iDentIfiCaTIon of cliNical and molecular drivers: the PREDICTION study.

BACKGROUND: Metastatic disease in tumors originating from the gastrointestinal tract can exhibit varying degrees of tumor burden at presentation. Some patients follow a less aggressive disease course, characterized by a limited number of metastatic sites, referred to as "oligo-metastatic disease" (OMD). The precise biological characteristics that define the oligometastatic behavior remain uncertain. In this study, we present a protocol designed to prospectively identify OMD, with the aim of proposing novel therapeutic approaches and monitoring strategies. METHODS: The PREDICTION study is a monocentric, prospective, observational investigation. Enrolled patients will receive standard treatment, while translational activities will involve analysis of the tumor microenvironment and genomic profiling using immunohistochemistry and next-generation sequencing, respectively. The first primary objective (descriptive) is to determine the prevalence of biological characteristics in OMD derived from gastrointestinal tract neoplasms, including high genetic concordance between primary tumors and metastases, a significant infiltration of T lymphocytes, and the absence of clonal evolution favoring specific driver genes (KRAS and PIK3CA). The second co-primary objective (analytic) is to identify a prognostic score for true OMD, with a primary focus on metastatic colorectal cancer. The score will comprise genetic concordance (> 80%), high T-lymphocyte infiltration, and the absence of clonal evolution favoring driver genes. It is hypothesized that patients with true OMD (score 3+) will have a lower rate of progression/recurrence within one year (20%) compared to those with false OMD (80%). The endpoint of the co-primary objective is the rate of recurrence/progression at one year. Considering a reasonable probability (60%) of the three factors occurring simultaneously in true OMD (score 3+), using a significance level of α = 0.05 and a test power of 90%, the study requires a minimum enrollment of 32 patients. DISCUSSION: Few studies have explored the precise genetic and biological features of OMD thus far. In clinical settings, the diagnosis of OMD is typically made retrospectively, as some patients who undergo intensive treatment for oligometastases develop polymetastatic diseases within a year, while others do not experience disease progression (true OMD). In the coming years, the identification of true OMD will allow us to employ more personalized and comprehensive strategies in cancer treatment. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT05806151.

Liquid Biopsy Testing for the Management of Patient with Non-Small Cell Lung Cancer Carrying a Rare Exon-20 EGFR Insertion.

Increasing evidence suggests that liquid biopsy might play a relevant role in the management of metastatic non-small cell lung cancer (NSCLC) patients. Here, we show how the Molecular Tumor Board (MTB) in our cancer center employed liquid biopsy to support therapeutic decisions in a patient with NSCLC carrying a rare EGFR mutation. A 44-year-old woman, never-smoker with an EGFR, ALK, and ROS1-negative lung adenocarcinoma and multiple brain metastases received systemic therapy and surgery before being referred to our Institute. The MTB suggested NGS testing of tumor biopsy that revealed a rare exon-20 EGFR insertion (p.His773dup; c.2315_2316insCCA) and EGFR amplification. The MTB recommended treatment with erlotinib and follow-up with liquid biopsy, by using both cell-free DNA (cfDNA) and circulating tumor cells (CTCs). An increase of EGFR mutation levels in cfDNA revealed resistance to treatment about 6 months before clinical progression. Extremely low levels of EGFR p.T790M were detected at progression. Based on preclinical data suggesting activity of osimertinib against EGFR exon-20 insertions, the MTB recommended treatment with brain and bone radiotherapy and osimertinib. A dramatic reduction of EGFR mutation levels in the cfDNA was observed after 4 weeks of treatment. The PET scan demonstrated a metabolic partial remission that was maintained for 9 months. This case supports the evidence that liquid biopsy can aid in the management of metastatic NSCLC. It also suggests that treatment with osimertinib might be a therapeutic option in patients with EGFR exon-20 insertions when a clinical trial is not available.

Ser/Thr kinases and polyamines in the regulation of non-canonical functions of elongation factor 1A.

The link between eukaryotic translation elongation factor 1A (eEF1A) and signal transduction pathways through the regulatory mechanism of phosphorylation has never been considered. In this review, we focus on the different kinases that recognize the Ser and Thr residues of the eEF1A1 and eEF1A2 isoforms and regulate their involvement in different cellular processes like cell survival and apoptosis. In this context, polyamines seem to play a role in the regulation of the translation elongation process by modulating the Ser/Thr kinases involved in the phosphorylation of translation elongation factors.

Diatomite biosilica nanocarriers for siRNA transport inside cancer cells.

BACKGROUND: Diatomite is a natural porous biomaterial of sedimentary origin, formed by fragments of diatom siliceous skeletons, called "frustules". Due to large availability in many areas of the world, chemical stability, and non-toxicity, these fossil structures have been widespread used in lot of industrial applications, such as food production, water extracting agent, production of cosmetics and pharmaceutics. However, diatomite is surprisingly still rarely used in biomedical applications. In this work, we exploit diatomite nanoparticles for small interfering ribonucleic acid (siRNA) transport inside human epidermoid cancer cells (H1355). METHODS: Morphology and composition of diatomite microfrustules (average size lower than 40µm) are investigated by scanning electron microscopy equipped by energy dispersive X-ray spectroscopy, Fourier transform infrared analysis, and photoluminescence measurements. Nanometric porous particles (average size lower than 450nm) are obtained by mechanical crushing, sonication, and filtering of micrometric frustules. siRNA bioconjugation is performed on both micrometric and nanometric fragments by silanization. RESULTS: In-vitro experiments show very low toxicity on exposure of the cells to diatomite nanoparticle concentration up to 300µg/ml for 72h. Confocal microscopy imaging performed on cancer cells incubated with siRNA conjugated nanoparticles demonstrates a cytoplasmatic localization of vectors. Gene silencing by delivered siRNA is also demonstrated. CONCLUSION: Our studies endorse diatomite nanoparticles as non-toxic nanocarriers for siRNA transport in cancer cells. GENERAL SIGNIFICANCE: siRNA is a powerful molecular tool for cancer treatment but its delivery is inefficient due to the difficulty to penetrate the cell membrane. siRNA-diatomite nanoconjugate may be well suited for delivery of therapeutic to cancer cells.

B-cell receptor-guided delivery of peptide-siRNA complex for B-cell lymphoma therapy.

BACKGROUND: Despite the clinical response of conventional anticancer therapy, including chemotherapeutic treatments, radiation therapy and corticosteroids, tumorigenic B-cell lymphomas show an incomplete response to clinical practices that result in a minimal residual disease (MRD) where few residual neoplastic cells undetected in vivo, replenish the cancer cell reservoir. This scenario, which is also shared with other cancer diseases, requires the development of strategies to advance in novel, selective targeting toward the tumorigenic cells that survive to the anticancer agents. METHODS: Here, we have taken advantage of the therapeutic properties of an idiotype specific peptide (pA20-36) that bind specifically to murine B-lymphoma cells in the setting of an anti cancer strategy, based on the selected delivery of electrostatic-based complex, peptide-siRNA. To this end, two engineered, arginine rich, peptides that included the pA20-36 targeting sequence were designed to bind fluorescent-labelled siRNA. One peptide presented 9 Arg at the C-terminal of pA20-36 whereas the other included 5 Arg at the N- and C-terminus, respectively. RESULTS: Compared to the control and random peptide-siRNA complexes, both pA20-36-siRNA complexes were endowed with the selective delivering of fluorescent-labelled siRNA toward the A20 murine B-cell lymphoma, as evaluated by cytofluorimetry and confocal microscopy, whereas fluorescent-labelled siRNA alone was not internalized in the selected cells. Compared to peptide controls, the use of the modified pA20-36 peptides complexed with siRNA anti-GAPDH and anti-Bcl2 showed a down-regulation in the expression levels of the corresponding genes. CONCLUSIONS: Peptide-siRNA complex can be suitable tool for both selective peptide-driven cell targeting and gene silencing. In this setting, the improvement of this strategy is expected to provide a safe and non-invasive approach for the delivery of therapeutic molecules.

Surgery for non-small cell lung cancer in younger patients: what are the differences?

BACKGROUND: Non-small cell lung cancer (NSCLC) in young adults is uncommon. The objective of this study was to evaluate the clinicopathological characteristics, outcomes and prognosis of people younger than 50 years old treated surgically for NSCLC. METHODS: A retrospective study was conducted using the institutional database of four thoracic surgery units to collect patients with NSCLC younger than 50 years who had undergone surgery. These patients were compared with older patients (>75-years) operated in the same institutions and in the same period. RESULTS: We identified 113 young patients and 347 older patients. Younger patients were more likely to be female, non-smokers, with fewer comorbidities. Younger patients were more likely to be symptomatic at the time of diagnosis. Risk factors for poor prognosis in younger patients were T-stage, and disease-free-interval less than 548 days. Kaplan-Meier analysis showed a lower five-year survival in older patients compared with the younger ones (66% vs 38%, p=0.001). CONCLUSIONS: In conclusion NSCLC in younger patients has some distinct clinicopathological characteristics. The overall-survival of young patients is better than in older patients. Young patients receive more complete and aggressive treatment that could explain better survival. Further prospective studies with larger patient populations are required, to clarify the biological and genetic variance of NSCLC in younger patients.

Patient satisfaction after pulmonary resection for lung cancer: a multicenter comparative analysis.

BACKGROUND: Patient satisfaction reflects the perception of the customer about the level of quality of care received during the episode of hospitalization. OBJECTIVE: To compare the levels of satisfaction of patients submitted to lung resection in two different thoracic surgical units. METHODS: Prospective analysis of 280 consecutive patients submitted to pulmonary resection for neoplastic disease in two centers (center A: 139 patients; center B: 141 patients; 2009-2010). Patients' satisfaction was assessed at discharge through the EORTC-InPatSat32 module, a 32-item, multi-scale self-administered anonymous questionnaire. Each scale (ranging from 0 to 100 in score) was compared between the two units. Multivariable regression and bootstrap were used to verify factors associated with the patients' general satisfaction (dependent variable). RESULTS: Patients from unit B reported a higher general satisfaction (91.5 vs. 88.3, p = 0.04), mainly due to a significantly higher satisfaction in the doctor-related scales (doctors' technical skill: p = 0.001; doctors' interpersonal skill: p = 0.008; doctors' availability: p = 0.005, and doctors information provision: p = 0.0006). Multivariable regression analysis and bootstrap confirmed that level of care in unit B (p = 0.006, bootstrap frequency 60%) along with lower level of education of the patient population (p = 0.02, bootstrap frequency 62%) were independent factors associated with a higher general patient satisfaction. CONCLUSION: We were able to show a different level of patient satisfaction in patients operated on in two different thoracic surgery units. A reduced level of patient satisfaction may trigger changes in the management policy of individual units in order to meet patients' expectations and improve organizational efficiency.

Risk Management Activities in a Lung Cancer Multidisciplinary Team at a Comprehensive Cancer Center: Results of a Prospective Analysis.

PURPOSE: The objective of the study was to highlight sources of harm that could negatively affect the lung cancer multidisciplinary team (MDT) activities to reduce the level of risk of each factor. METHODS: A modified Delphi approach was used by a board of multi-health care professionals of the lung cancer MDT to identify the main processes, subprocesses, and risk factors of the multidisciplinary pathway of patients with lung cancer. A semiquantitative matrix was built with a five-point scale for probability of harm (likelihood) and severity of harm (consequences) according to the international risk management standards (ISO 31000-2018). The risk level was calculated by multiplying likelihood × consequences. Mitigation strategies have been identified and applied by the MDT to reduce risks to acceptable levels. RESULTS: Three main processes (outpatient specialist visit, MDT discussion, and MDT program implementation), eight related subprocesses, and 16 risk factors were identified. Four risk factors (25%) were related to outpatient specialist visit, seven (43.75%) to case discussion, and five (31.25%) to program implementation. Overall, two risk factors were assigned a low-risk level (12.5%), 11 a moderate-risk level (68.75%), one (6.25%) a high-risk level, and two (12.5%) a very high-risk level. After the implementation of mitigation measures, the new semiquantitative risk analysis showed a reduction in almost all hazardous situations: two risk factors (12.5%) were given a very low level, six (37.5%) a low level, seven (43.75%) a moderate level, and one (6.25%) a very high level. CONCLUSION: An interdisciplinary risk assessment analysis is applicable to MDT activities by using an ad hoc risk matrix: if the hazard is identified and monitored, the risk could be reduced and managed in a short time.

Oligo-Metastatic Cancers: Putative Biomarkers, Emerging Challenges and New Perspectives.

Some cancer patients display a less aggressive form of metastatic disease, characterized by a low tumor burden and involving a smaller number of sites, which is referred to as "oligometastatic disease" (OMD). This review discusses new biomarkers, as well as methodological challenges and perspectives characterizing OMD. Recent studies have revealed that specific microRNA profiles, chromosome patterns, driver gene mutations (ERBB2, PBRM1, SETD2, KRAS, PIK3CA, SMAD4), polymorphisms (TCF7L2), and levels of immune cell infiltration into metastases, depending on the tumor type, are associated with an oligometastatic behavior. This suggests that OMD could be a distinct disease with specific biological and molecular characteristics. Therefore, the heterogeneity of initial tumor burden and inclusion of OMD patients in clinical trials pose a crucial methodological question that requires responses in the near future. Additionally, a solid understanding of the molecular and biological features of OMD will be necessary to support and complete the clinical staging systems, enabling a better distinction of metastatic behavior and tailored treatments.

The magic spot ppGpp influences in vitro the molecular and functional properties of the elongation factor 1α from the archaeon Sulfolobus solfataricus.

Guanosine tetra-phosphate (ppGpp), also known as "magic spot I", is a key molecule in the stringent control of most eubacteria and some eukarya. Here, we show that ppGpp affects the functional and molecular properties of the archaeal elongation factor 1α from Sulfolobus solfataricus (SsEF-1α). Indeed, ppGpp inhibited archaeal protein synthesis in vitro, even though the concentration required to get inhibition was higher than that required for the eubacterial and eukaryal systems. Regarding the partial reactions catalysed by SsEF-1α the effect produced by ppGpp on the affinity for aa-tRNA was lower than that measured in the presence of GTP but higher than that for GDP. Magic spot I was also able to bind SsEF-1α with an intermediate affinity in comparison to that displayed by GDP and GTP. Furthermore, ppGpp inhibited the intrinsic GTPase of SsEF-1α with a competitive behaviour. Finally, the binding of ppGpp to SsEF-1α rendered the elongation factor more resistant to heat treatment and the analysis of the molecular model of the complex between SsEF-1α and ppGpp suggests that this stabilisation arises from the charge optimisation on the surface of the protein.

Early experience with uniportal robotic thoracic surgery lobectomy.

Background: Invasiveness is considered one of the cornerstones of every field of surgery, and video-assisted thoracoscopic (VATS) approaches are now routinely used worldwide to perform pulmonary resections. Recently, robotic-assisted thoracic surgery (RATS) has become the preferred technique in many centers; it is routinely performed using three or four ports with at least one service incision, contrasting with the real concept of invasiveness, especially when compared to uniportal VATS (U-VATS). Hereby, we present our early experience with uniportal RATS (U-RATS) pulmonary resections for early-stage lung cancer. Technical details of surgical steps are accurately described and commented on. Results: Twenty-four consecutive patients with lung cancer underwent U-RATS anatomical pulmonary resections at our institute. All procedures were completed with the uniportal approach. The mean operative time was 210 min (range 120-350); in the last 10 cases, the operative time was significantly reduced (180 min) compared to the first 10 cases (232 min) (p < 0.02), showing a very fast learning curve. The postoperative pain score was comparable to that for U-VATS and was constantly low. Conclusions: U-RATS is a safe and feasible technique, combining the advantages of U-VATS with the well-known advantages of robotic surgery.

Surgery in Small-Cell Lung Cancer.

Small-cell lung cancer (SCLC) is one of the most aggressive tumors, with a rapid growth and early metastases. Approximately 5% of SCLC patients present with early-stage disease (T1,2 N0M0): these patients have a better prognosis, with a 5-year survival up to 50%. Two randomized phase III studies conducted in the 1960s and the 1980s reported negative results with surgery in SCLC patients with early-stage disease and, thereafter, surgery has been largely discouraged. Instead, several subsequent prospective studies have demonstrated the feasibility of a multimodality approach including surgery before or after chemotherapy and followed in most studies by thoracic radiotherapy, with a 5-year survival probability of 36-63% for patients with completely resected stage I SCLC. These results were substantially confirmed by retrospective studies and by large, population-based studies, conducted in the last 40 years, showing the benefit of surgery, particularly lobectomy, in selected patients with early-stage SCLC. On these bases, the International Guidelines recommend a surgical approach in selected stage I SCLC patients, after adequate staging: in these cases, lobectomy with mediastinal lymphadenectomy is considered the standard approach. In all cases, surgery can be offered only as part of a multimodal treatment, which includes chemotherapy with or without radiotherapy and after a proper multidisciplinary evaluation.

Thymomectomy plus total thymectomy versus simple thymomectomy for early-stage thymoma without myasthenia gravis: a European Society of Thoracic Surgeons Thymic Working Group Study.

OBJECTIVES: Resection of thymic tumours including the removal of both the tumour and the thymus gland (thymothymectomy; TT) is the procedure of choice and is recommended in most relevant articles in the literature. Nevertheless, in recent years, some authors have suggested that resection of the tumour (simple thymomectomy; ST) may suffice from an oncological standpoint in patients with early-stage thymoma who do not have myasthenia gravis (MG) (non-MG). The goal of our study was to compare the short- and long-term outcomes of ST versus TT in non-MG early-stage thymomas using the European Society of Thoracic Surgeons thymic database. METHODS: A total of 498 non-MG patients with pathological stage I thymoma were included in the study. TT was performed in 466 (93.6%) of 498 patients who had surgery with curative intent; ST was done in 32 (6.4%). The completeness of resection, the rate of complications, the 30-day mortality, the overall recurrence and the freedom from recurrence were compared. We performed crude and propensity score-adjusted comparisons by surgical approach (ST vs TT). RESULTS: TT showed the same rate of postoperative complications, 30-day mortality and postoperative length of stay as ST. The 5-year overall survival rate was 89% in the TT group and 55% in the ST group. The 5-year freedom from recurrence was 96% in the TT group and 79% in the ST group. CONCLUSION: Patients with early-stage thymoma without MG who have a TT show significantly better freedom from recurrence than those who have an ST, without an increase in postoperative morbidity rate.

Angiogenesis and epidermal growth factor receptor inhibitors in non-small cell lung cancer.

Several preclinical studies suggested a potential benefit from combined treatment with inhibitors of epidermal growth factor receptor (EGFR) and angiogenesis, both effective in patients with advanced non-small-cell lung cancer (NSCLC). In pretreated patients with advanced EGFR wild type NSCLC, bevacizumab plus erlotinib improved progression-free survival as second-line therapy in the BeTa study and as maintenance therapy in the ATLAS trial, although the benefit was modest and did not translate into an advantage in overall survival. Disappointing results were reported with oral VEGF inhibitors plus erlotinib in pretreated patients with EGFR wild type NSCLC. On the contrary, erlotinib plus bevacizumab or ramucirumab showed a clinically relevant improvement of progression-free survival in naïve patients with EGFR mutations, leading to the approval of these two regimens as first-line treatment of NSCLC patients with EGFR mutant tumors. Several clinical studies are evaluating the feasibility and activity of osimertinib plus bevacizumab or ramucirumab. However, limits that could affect its use in clinical practice are the need of an intravenous infusion for angiogenesis inhibitors, the increased incidence of treatment associated adverse events, the exclusion of patients with tumors located in central position or at risk of hemorrhage. The identification of predictive biomarkers is an important goal of research to optimize the combined use of these agents.

Immunotherapy in Small Cell Lung Cancer.

Small-cell lung cancer (SCLC) is an aggressive tumor type with limited therapeutic options and poor prognosis. Chemotherapy regimens containing platinum represent the cornerstone of treatment for patients with extensive disease, but there has been no real progress for 30 years. The evidence that SCLC is characterized by a high mutational burden led to the development of immune-checkpoint inhibitors as single agents or in combination with chemotherapy. Randomized phase III trials demonstrated that the combination of atezolizumab (IMpower-133) or durvalumab (CASPIAN) with platinum-etoposide chemotherapy improved overall survival of patients with extensive disease. Instead, the KEYNOTE-604 study demonstrated that the addition of pembrolizumab to chemotherapy failed to significantly improve overall survival, but it prolonged progression-free survival. The safety profile of these combinations was similar with the known safety profiles of all single agents and no new adverse events were observed. Nivolumab and pembrolizumab single agents showed anti-tumor activity and acceptable safety profile in Checkmate 032 and KEYNOTE 028/158 trials, respectively, in patients with SCLC after platinum-based therapy and at least one prior line of therapy. Future challenges are the identification predictive biomarkers of response to immunotherapy in SCLC and the definition of the role of immunotherapy in patients with limited stage SCLC, in combination with radiotherapy or with other biological agents.

Genetic trajectory and immune microenvironment of lung-specific oligometastatic colorectal cancer.

Genetics and immunologic dynamics pushing the evolution of colorectal cancer (CRC) from the primary tumor to the metastases are largely unknown; cancer heterogeneity makes challenging both therapy and mechanistic studies. We selected patients developing CRC with lung-limited metastatic disease as only illness during their life in order to find any relevant genotype-phenotype relationship. Analysis of 523 cancer-relevant genes and of immune cells infiltration in primary and metastatic tissues revealed atypical genomic trajectories (TMB decrease, KRAS and SMAD4 regressive mutations), specific genetic events (ERBB2 point mutations) and scarce T-cell infiltration. These insights provide novel information in oligometastatic CRC biology and new perspectives for cancer monitoring and anti-cancer therapeutic strategies.

The safety of atezolizumab plus chemotherapy for the treatment of metastatic lung cancer.

INTRODUCTION: Atezolizumab is a humanized monoclonal antibody against PD-L1 capable of enhancing antitumor immune activity, with a demonstrated activity as single agent in patients with advanced non-small-cell lung cancer (NSCLC). AREAS COVERED: This review summarizes the clinical data emerging from randomized clinical studies with atezolizumab in NSCLC and small-cell lung cancer (SCLC), focusing in particular on the efficacy and safety data regarding the combinations of atezolizumab plus chemotherapy in the IMpower studies. EXPERT OPINION: A significant improvement in progression-free survival and in overall survival was observed in IMpower 130 and 150 (NSCLC non-squamous) and 133 (SCLC), with an acceptable safety profile. In particular, the most common immune-related adverse events were rash (18-28% of patients), hypothyroidism (8-15%), hepatitis (5-17%), pneumonitis (2-7%), and colitis (1.5-2.3%). The safety profile of atezolizumab in combination with chemotherapy was consistent with the known adverse events related to single-agent atezolizumab and no new adverse events were observed. Ongoing studies will evaluate the role of atezolizumab in other settings (adjuvant and neoadjuvant) and in combination with chemotherapy and radiotherapy for patients with locally advanced NSCLC and the role of predictive factors (B-FAST study).

[Benign retroperitoneal schwannoma: a case report and review of the literature]. / Schwannoma benigno del retroperitoneo: caso clinico e revisione della letteratura.

Retroperitoneal schwannoma is a very rare benign tumour that accounts for only a small percentage of retroperitoneal tumours. The preoperative diagnosis is difficult and the only treatment is complete surgical excision. The authors report their experience with a case of a voluminous retroperitoneal mass in a 42-year- old male patient, incidentally discovered during a diagnostic search for a blunt abdominal trauma. Because of the unclear origin of this mass, the patient underwent periodic radiological and ultrasonographic examinations. Three years later, owing to a slight increase in this mass and vague abdominal discomfort reported by the patient, surgical excision was performed. Histological examination of the surgical specimen revealed an "ancient schwannoma". The patient is alive and well and has had no recurrence in the twenty months since surgery. The authors, after a short discussion of the subject, go on to examine the diagnostic and therapeutic treatments of this rare benign neoplasm, which always arouses lively clinical and scientific interest.

Internalization kinetics and cytoplasmic localization of functionalized diatomite nanoparticles in cancer cells by Raman imaging.

Porous biosilica nanoparticles obtained from diatomites (DNPs) have been recently demonstrated to be non-toxic nanovectors of therapeutic agents in cancer cells. In this work, the internalization kinetics and intracellular spatial distribution of functionalized DNPs incubated with human lung epidermoid carcinoma cell line (H1355) up to 72 hours are investigated by Raman imaging. The label-free Raman results are compared with confocal fluorescence microscopy and photoluminescence (PL) data. Raman bands specifically assigned to DNPs and cellular components provide evidence that the nanovectors are internalized and co-localize with lipid environments. A considerable DNPs uptake in cells is observed within 6 hours, with equilibrium being achieved after 18 hours. The obtained data show the presence of DNPs up to 72 hours, without damage to cell viability or morphology. The PL measurements performed on DNPs not penetrating the cells at different incubation times are strongly correlated with the results obtained by Raman imaging and confocal microscopy analyses.

Bioengineered Silicon Diatoms: Adding Photonic Features to a Nanostructured Semiconductive Material for Biomolecular Sensing.

Native diatoms made of amorphous silica are first converted into silicon structures via magnesiothermic process, preserving the original shape: electron force microscopy analysis performed on silicon-converted diatoms demonstrates their semiconductor behavior. Wet surface chemical treatments are then performed in order to enhance the photoluminescence emission from the resulting silicon diatoms and, at the same time, to allow the immobilization of biological probes, namely proteins and antibodies, via silanization. We demonstrate that light emission from semiconductive silicon diatoms can be used for antibody-antigen recognition, endorsing this material as optoelectronic transducer.