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Innovative Medicines & Omics Biocompatibility of nanomaterials

Unfortunately, there have been many cases where concerns are particularly critical for nanomaterials due
promising nanomaterials performed well in the laboratory to their unique and complex properties. Environmental
but failed in vivo. These failures often stem from poor studies on nanoparticle degradation have underscored the
biocompatibility. For example, nanoparticles not designed importance of understanding material fate as a determinant
to avoid immune surveillance may be rapidly cleared from of long-term safety. 14
circulation, or, more concerningly, provoke dangerous To meet these expectations, developers must prioritize
responses. Studies on targeted delivery have shown the the selection of biocompatible materials and implement
importance of anticipating such reactions during the surface modifications to improve safety. Organic
design phase, underscoring that the clinical success of nanomaterials, such as liposomes or biodegradable
nanomaterials hinges on proactive biocompatibility polymers, are favored in regulatory assessments due to their
assessment and modulation. 10
inherent capacity to break down into harmless byproducts.
2.2. Comparison with conventional biomaterials On the other hand, inorganic materials such as iron oxide
or gold may offer advantages in imaging or durability,
Nanomaterials exhibit fundamentally different biological but usually require surface coatings to reduce toxicity
interactions compared to traditional biomaterials. While and prevent accumulation in tissues. These strategies
bulk materials such as metals and polymers are typically are supported by recent studies showing the feasibility
inert and used for their mechanical strength, nanomaterials of safely using inorganic nanoparticles in biomedical
are reactive, customizable, and operate at a scale that applications through engineered surface modifications.
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enables intimate interaction with biological structures. Additional research has further pointed out the need to
These features allow for exciting possibilities in medicine— manage potential immune effects from inorganic particles,
such as targeted drug delivery or real-time monitoring— highlighting the value of immunomodulatory surface
but they also introduce significant challenges. Studies design. 16
on nanoparticle surface engineering have shown that
poorly designed nanomaterials can adsorb proteins non- 2.4. Foundation for engineering nanomedicines
specifically, trigger immune responses, or cause cellular
damage. 11 Biocompatibility must be integrated into nanomaterial
design from the outset—it is not a parameter that can
Unlike conventional implants, which typically remain be retroactively optimized. Every physicochemical
inert and static within the body, nanomaterials are often characteristic of the nanomaterial, including size, shape,
intended to move, respond dynamically, or break down surface charge, texture, and chemical composition, plays
after fulfilling their function. Their tiny size allows a pivotal role in determining biological interactions.
them to enter cells more easily, but it also increases One widely used method to enhance biocompatibility is
their accumulation in tissues. For instance, particles PEGylation, whereby polyethylene glycol (PEG) chains are
smaller than 100 nanometers are great for intracellular grafted onto nanoparticle surfaces. This modification helps
delivery; however, if they are not biodegradable, they may the material stay in the bloodstream longer and reduces
accumulate and cause harm over time—a concern raised detection by the immune system. PEGylation, along with
in earlier work on nanoparticle design. Particle shape also hydrophilic surface coatings, has proven highly effective
12
significantly influences biological interactions. Spherical in improving compatibility, as noted in several design-
nanoparticles tend to be taken up more readily, while rod- focused studies. 10,11
shaped particles exhibit distinct uptake pathways and may
interact with immune cells differently, potentially altering Surface charge also plays a delicate role. Positively
their safety profile. 13 charged particles are more likely to enter cells, thanks to
their attraction to the negatively charged cell membranes.
2.3. Regulatory emphasis on biocompatibility However, this benefit comes with a downside—a higher
Health regulatory agencies around the world—including propensity for cytotoxicity and pro-inflammatory
the U.S. FDA and the European Medicines Agency responses. On the other hand, neutral or slightly negative
(EMA)—place a strong emphasis on biocompatibility in particles are usually better tolerated, though they might
the evaluation of nanomedicine products. Developers are not be taken up as efficiently. Striking the right balance is
expected not only to prove that a treatment works but critical, as highlighted in immunological studies focused
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on nanomaterial-host interactions.
also to provide detailed evidence about how the material
behaves in the body. Key questions include whether the Another aspect that influences biocompatibility
material exhibits toxicity, elicits immune responses, or is surface energy. When a nanoparticle enters the
how it is metabolized and cleared from the body. These bloodstream, it quickly gets coated with proteins, forming

Volume 2 Issue 3 (2025) 46 doi: 10.36922/IMO025210024