Microfat and Nanofat are both autologous adipose-derived grafting methods that have clear differences in characteristics. As later discussed, we mention why the terms should be used in a standardized fashion with each term reserved for that specific fat grafting process. Nanofat has no live adipose cells and no volumizing qualities and Microfat the opposite.
Fat grafting for cosmetic filling and facial reconstruction has been around since the late 1800s. In recent years, the process has been refined by using finer and more processed adipose injections in multiple tissue layers if possible . This has been associated with an increase of survival rates. This is due to the surgical excision and low negative-pressure aspiration with large-bore cannulas minimizing adipocyte damage during fat grafting . It is generally accepted that a less traumatic approach to harvesting and processing the fat will lead to better outcomes. The use of stem cells in cosmetics and reconstruction is rapidly becoming popular in fat grafting. More specifically, the use of adipose stem cells for the treatment of scars . Obtaining regenerative cells from adipose tissue can be done in two ways: Enzymatic and mechanical .
Copcu makes an argument for abandoning the use of Nanofat. We disagree with this for the aforementioned reasons. Moreover, the use of Nanofat is becoming popular and use of the Nanofat/ Microfat terminology is widespread. The issue is the occasional misunderstanding of the terms in the literature. However, there seems to be confusion with the use of Nanofat versus Microfat as seen in the paper by Verpaele for the use to fill in a lip scar defect . We use both adipose-derived stem cells (ADSC) and extensively processed fat frequently in our clinic. It appears the use of Nanofat isn’t standardized. The highly processed fat can be injected with fine cannulas for small corrections which we call Micro Fat injections. Our use for the term Nanofat is for the injection of ADSC. The following will describe the differences between Nanofat and Microfat and the reasoning for the standardization of nomenclature.
Microfat is small clumps of fat that are derived from lipoaspirate. The technique used for Microfat in cosmetic filling or facial reconstruction can be used as an isolated procedure or combined with another one . Survival rates and cosmetic outcomes for Microfat injections is better with multiple layers of fat injection as opposed to a large clump of Microfat in a single location. It is broken down so that it may be injected with fine cannulas. Our process does not use collagenase but is simply a method to mechanically break down the aspirate into usable material the particles injected are well above the upper limit of Nanoparticles (100 Nanometers in diameter).
Our method is as follows:
a) 200cc to 500cc of tumescent solutions (50cc of lidocaine with epinephrine in 500cc of normal saline) is infiltrated into the anterior abdominal fat pad or the thighs.
b) 50 to 150cc of lipoaspirate is removed using a 1.5mm Byron harvesting cannula under hand pressure. Mechanical liposuction is avoided.
c) Gravity drainage is used to remove the tumescent fluid and oily layer (occasionally the aspirate is centrifuged if there is not adequate gravity separation).
d) The fat aspirate is broken down with Tulip sizers
(sequential fragmenters) until it can pass through a 22-gauge
blunt tip needle. (Figure 1) shows the appearance of the Microfat
e) The fat is then injected into the predetermined area (soft
tissue defect). (Figure 2) shows a patient treated with Microfat.
Nanofat is made when the ADSC is processed from the
lipoaspirate with all the adipose cells removed. Using condensed
Nanofat combined with fat grafts in a novel technique to improve
atrophic facial scars by raising both the surface and the bottom
of the affected area is the best way to use nanofat . The use
of Nanofat on scars has both a cosmetic improvement but has
been show histologically to improve the dermal layer. It has no
filling qualities and is useful for the stimulation of collagen and
elastic and useful in scar treatment and facial rejuvenation. It is
the remnant of the lipoaspirate consisting of the stromal vascular
fraction along with cytokines, epidermal growth factors, collagen stim, and intracellular hormones .
Our method is as follows:
a) 200cc to 500cc of tumescent solutions (50cc of lidocaine
with epinephrine in 500cc of normal saline) is infiltrated into the
anterior abdominal fat pad or the thighs
b) 50 to 150cc of lipoaspirate is removed using a 1.5mm
Byron harvesting cannula
c) Gravity drainage is used to remove the tumescent fluid
and oily layer (occasionally the aspirate is centrifuged if there is
not adequate gravity separation).
d) The fat aspirate is broken down with Tulip sizers.
(Sequential fragments) until it can pass through a 22-gauge blunt
e) The processed liquid Microfat is then placed through a
filter device (Tulip) to generate a Nanofat liquid. (Figure 3) shows the appearance of the Nanofat before injection.
f) The Nanofat is then injected into the predetermined
area via a 27-gauge needle in a mesotherapy technique. (Figure
4) shows a picture of a patient with burn scars before and after
Microfat is a term that should only be reserved for adipocytecontaining
volumizer. This lipoaspirate is broken down into a fairly
thin liquid that can be injected via a 22-gauge needle or smaller.
Micro fat is a filler and contains live adipose cells. Nanofat is a
term that should only be reserved for lipoaspirate broken down
into a fairly thin liquid that has NO adipose cell and is the stromal
vascular fraction of the lipoaspirate. It has NO volumizing qualities
and serves as a regenerative modality. Nanofat is the residual
of processed lipoaspirate that is broken down into Microfat.
The Nanofat is isolated when the adipocytes are removed from Microfat. The resultant stromovascular fraction contains different
types of cells such as endothelial cells, monocytes, macrophages,
granulocytes and lymphocytes.
The stromal vascular fraction also includes a substantial
amount of mesenchymal stem cells (adipose-derived stem cells).
These multipotent stem cells have the ability to form fibroblastlike
colonies in vitro. Unlike other sources of multipotent stem
cells, these multipotent stem cells are found in high quantities
in lipoaspirate. Adipose-derived stem cells have an extensive
proliferative capacity and the ability to differentiate into other
mesenchymal cells. Other terms use for adipose-derived non-augmenting biologics include adipose-derived stem cells ADSC
and adipose-derived exosomes. True nanoparticles have sizes
from 1 to 100 nanometer portions of the stromal vascular fraction
fit that size criteria . For example, enzymes typically range from
100 to 1000nm.
Many peptides fit into this nanometer range. With Nanofat,
even though all of the components are not nanoparticles, several
are. Therefore, we feel comfortable with the term Nanofat
. The impact of Nanofat on skin rejuvenation is not entirely
understood. Several studies imply the potential effectiveness
of Nanofat [4,9,10]. Long-term follow-ups on multiple patients
that have undergone autologous fat injections showed that the
absorption rate varies considerably in each individual case but
was estimated to be 40-60% of the injected fat. Furthermore, the
long-term follow-ups proved that with final corrections after two
or more repetitions of fat injections the longevity of the injections
persisted for many years with one of the longest being proved to
be more than 12 years [11,12].
Additionally, many issues come to play a role in the clinical
longevity of correction after autologous fat transfer/injections
and it is less dependent on the harvesting and reinjection
methods. The degree of augmentation is a determining factor
which results from the amount of fibrosis induced along with the
number of viable fat cell grafts. That number also depends on the
anatomic site, the mobility and vascularity of the recipient tissue
or any underlying causes and diseases .