Collagen-Binding Nanoparticles: A Scoping Review of Methods and Outcomes

Fabrication of Nanocollagen Using Enhanced Cryogenic Milling Method with Graphene Oxide

Objective

Collagen, a widely used natural biomaterial polymer in skin tissue engineering, can be innovatively processed into nanocollagen through cryogenic milling to potentially enhance skin tissue healing. Although various methods for fabricating nanocollagen have been documented, there is no existing study on the fabrication of nanocollagen via cryogenic milling, specifically employing graphene oxide as separators to prevent agglomeration.

Methods

In this study, three research groups were created using cryogenic milling: pure nanocollagen (Pure NC), nanocollagen with 0.005% graphene oxide (NC + 0.005% GO), and nanocollagen with 0.01% graphene oxide (NC+0.01% GO). Characterization analyses included transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), zeta potential (ZP), and polydispersity index (PDI).

Results

TEM and SEM analysis revealed that nanocollagen groups alone exhibited particle sizes of less than 100 nm. FTIR spectroscopic investigations indicated the presence of amide A, B, and I, II, and III (1800 to 800 cm-1) in all nanocollagen study groups, with the characteristic C-O-C stretching suggesting the incorporation of graphene oxide (GO). XRD data exhibited broadening of the major peak as the proportion of GO increased from pure NC to the nanocollagen groups with GO. Zeta potential measurements indicated electrostatic attraction of the samples to negatively charged surfaces, accompanied by sample instability. PDI results depicted size diameters ranging from 800 to 1800 nm, indicating strong polydispersity with multiple size populations.

Conclusion

This research demonstrated that collagen can be successfully fabricated into nanoparticles with sizes smaller than 100 nm.

Collagen-Binding Nanoparticles for Paclitaxel Encapsulation and Breast Cancer Treatment

In this study, we developed a novel hybrid collagen-binding nanocarrier for potential intraductal administration and local breast cancer treatment. The particles were formed by the encapsulation of nanostructured lipid carriers (NLCs) containing the cytotoxic drug paclitaxel within a shell of poly(N-isopropylacrylamide) (pNIPAM), and were functionalized with SILY, a peptide that binds to collagen type I (which is overexpressed in the mammary tumor microenvironment) to improve local retention and selectivity. The encapsulation of the NLCs in the pNIPAM shell increased nanoparticle size by approximately 140 nm, and after purification, a homogeneous system of hybrid nanoparticles (∼96%) was obtained. The nanoparticles exhibited high loading efficiency (<76%) and were capable of prolonging paclitaxel release for up to 120 h. SILY-modified nanoparticles showed the ability to bind to collagen-coated surfaces and naturally elaborated collagen. Hybrid nanoparticles presented cytotoxicity up to 3.7-fold higher than pNIPAM-only nanoparticles on mammary tumor cells cultured in monolayers. In spheroids, the increase in cytotoxicity was up to 1.8-fold. Compared to lipid nanoparticles, the hybrid nanoparticle modified with SILY increased the viability of nontumor breast cells by up to 1.59-fold in a coculture model, suggesting the effectiveness and safety of the system.

Nanocarriers of shRNA-Runx2 directed to collagen IV as a nanotherapeutic system to target calcific aortic valve disease

Runx2 is a key transcription factor involved in valvular interstitial cells (VIC) osteodifferentiation, a process actively entwined with the calcific aortic valve disease (CAVD). We hypothesize that a strategy intended to silence Runx2 could be a valuable novel therapeutic option for CAVD. To this intent, we aimed at (i) developing targeted nanoparticles for efficient delivery of short hairpin (sh)RNA sequences specific for Runx2 to the aortic valve employing a relevant mouse model for CAVD and (ii) investigate their therapeutic potential in osteoblast-differentiated VIC (oVIC) cultivated into a 3D scaffold. Since collagen IV was used as a target, a peptide that binds specifically to collagen IV (Cp) was conjugated to the surface of lipopolyplexes encapsulating shRNA-Runx2 (Cp-LPP/shRunx2). The results showed that Cp-LPP/shRunx2 were (i) cytocompatible; (ii) efficiently taken up by 3D-cultured oVIC; (iii) diminished the osteodifferentiation of human VIC (cultured in a 3D hydrogel-derived from native aortic root) by reducing osteogenic molecules expression, alkaline phosphatase activity, and calcium concentration; and (iv) were recruited in aortic valve leaflets in a murine model of atherosclerosis. Taken together, these data recommend Cp-LPP/shRunx2 as a novel targeted nanotherapy to block the progression of CAVD, with a good perspective to be introduced in practical use.

Sustainable Biodegradable Biopolymer-Based Nanoparticles for Healthcare Applications

Biopolymeric nanoparticles are gaining importance as nanocarriers for various biomedical applications, enabling long-term and controlled release at the target site. Since they are promising delivery systems for various therapeutic agents and offer advantageous properties such as biodegradability, biocompatibility, non-toxicity, and stability compared to various toxic metal nanoparticles, we decided to provide an overview on this topic. Therefore, the review focuses on the use of biopolymeric nanoparticles of animal, plant, algal, fungal, and bacterial origin as a sustainable material for potential use as drug delivery systems. A particular focus is on the encapsulation of many different therapeutic agents categorized as bioactive compounds, drugs, antibiotics, and other antimicrobial agents, extracts, and essential oils into protein- and polysaccharide-based nanocarriers. These show promising benefits for human health, especially for successful antimicrobial and anticancer activity. The review article, divided into protein-based and polysaccharide-based biopolymeric nanoparticles and further according to the origin of the biopolymer, enables the reader to select the appropriate biopolymeric nanoparticles more easily for the incorporation of the desired component. The latest research results from the last five years in the field of the successful production of biopolymeric nanoparticles loaded with various therapeutic agents for healthcare applications are included in this review.

Capturing the spatial and temporal dynamics of tumor stroma for on-chip optimization of microenvironmental targeting nanomedicine

Malignant cells grow in a complex microenvironment that plays a key role in cancer progression. The "dynamic reciprocity" existing between cancer cells and their microenvironment is involved in cancer differentiation, proliferation, invasion, metastasis, and drug response. Therefore, understanding the molecular mechanisms underlying the crosstalk between cancer cells and their surrounding tissue (i.e., tumor stroma) and how this interplay affects the disease progression is fundamental to design and validate novel nanotherapeutic approaches. As an important regulator of tumor progression, metastasis and therapy resistance, the extracellular matrix of tumors, the acellular component of the tumor microenvironment, has been identified as very promising target of anticancer treatment, revolutionizing the traditional therapeutic paradigm that sees the neoplastic cells as the preferential objective to fight cancer. To design and to validate such a target therapy, advanced 3D preclinical models are necessary to correctly mimic the complex, dynamic and heterogeneous tumor microenvironment. In addition, the recent advancement in microfluidic technology allows fine-tuning and controlling microenvironmental parameters in tissue-on-chip devices in order to emulate the in vivo conditions. In this review, after a brief description of the origin of tumor microenvironment heterogeneity, some examples of nanomedicine approaches targeting the tumor microenvironment have been reported. Further, how advanced 3D bioengineered tumor models coupled with a microfluidic device can improve the design and testing of anti-cancer nanomedicine targeting the tumor microenvironment has been discussed. We highlight that the presence of a dynamic extracellular matrix, able to capture the spatiotemporal heterogeneity of tumor stroma, is an indispensable requisite for tumor-on-chip model and nanomedicine testing.

Targeted Cancer Therapy via pH-Functionalized Nanoparticles: A Scoping Review of Methods and Outcomes

(1) Background: In recent years, several studies have described various and heterogenous methods to sensitize nanoparticles (NPs) to pH changes; therefore, in this current scoping review, we aimed to map current protocols for pH functionalization of NPs and analyze the outcomes of drug-loaded pH-functionalized NPs (pH-NPs) when delivered in vivo in tumoral tissue. (2) Methods: A systematic search of the PubMed database was performed for all published studies relating to in vivo models of anti-tumor drug delivery via pH-responsive NPs. Data on the type of NPs, the pH sensitization method, the in vivo model, the tumor cell line, the type and name of drug for targeted therapy, the type of in vivo imaging, and the method of delivery and outcomes were extracted in a separate database. (3) Results: One hundred and twenty eligible manuscripts were included. Interestingly, 45.8% of studies (n = 55) used polymers to construct nanoparticles, while others used other types, i.e., mesoporous silica (n = 15), metal (n = 8), lipids (n = 12), etc. The mean acidic pH value used in the current literature is 5.7. When exposed to in vitro acidic environment, without exception, pH-NPs released drugs inversely proportional to the pH value. pH-NPs showed an increase in tumor regression compared to controls, suggesting better targeted drug release. (4) Conclusions: pH-NPs were shown to improve drug delivery and enhance antitumoral effects in various experimental malignant cell lines.